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If your towels come out of the wash smelling worse than they went in, the problem is almost never your washing machine. Mildew and musty smells live in the fabric itself, and regular detergent alone often leaves those odor-causing residues right where they are. The products below are the ones that actually strip that smell out — some by killing the bacteria behind it, some by soaking it out of the fibers, and some by leaving a long-lasting fresh scent that keeps working after the dryer stops. This shortlist covers the different ways to attack a mildew smell so you can pick the method that matches your laundry problem.
This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
Some of these work in the rinse cycle while others go straight into the drum, so the right choice depends on whether you are chasing bacteria or chasing scent. Every pick here is a different tool against the same enemy, and matching the tool to the smell is the whole game with the Best Detergent for Mildew Smell.
Top Picks
How To Choose The Best Detergent for Mildew Smell
Match the method to the smell
Mildew smell on towels and bedding usually points to bacteria that have settled deep into the fibers over many washes. A rinse-cycle additive is built to tackle that, because it works in the final rinse where a regular detergent never reaches. A scent booster, by contrast, goes into the drum before the clothes and leans on long-lasting fragrance rather than germ-killing. If your problem is set-in stains that carry odor with them, an oxygen-boosted powder that soaks before the wash is often the more direct route. None of these methods is wrong — they simply solve different versions of the same problem.
Side-by-Side Comparison
| Model | Best For | Form | Size | Where It Goes | Amazon |
|---|---|---|---|---|---|
| Downy Unstopables Scent Booster Beads★ Best Overall | Long-lasting freshness | Beads | 24 oz | Washer drum | Amazon |
| Lysol Laundry SanitizerToughest Odors | Killing odor bacteria | Liquid | 90 oz | Rinse cycle | Amazon |
| Gain Hibiscus Hula Fabric Rinse & Renew | Pet odor removal | Liquid rinse | 48 fl oz | Rinse cycle | Amazon |
| ARM & HAMMER Plus OxiClean with Odor Blasters | Stains plus odor | Liquid detergent | 200.2 fl oz | Detergent dispenser | Amazon |
| Biz Laundry Detergent Powder | Set-in stains and odor | Powder | 37.5 oz | Washer drum | Amazon |
Detailed Reviews
1. Downy Unstopables Fresh Scent 24 oz
Our pick — over 4.5★ from 129,000+ verified ratings; the strongest balance of quality and price.
The crowd favorite that keeps a fresh scent alive for weeks after the dryer stops.
If your mildew problem shows up as towels that smell fine out of the washer and sour three days later in the closet, this is the one to reach for first. Downy Unstopables are scent booster beads — tiny pellets of concentrated fragrance that you toss into the drum before the fabrics. That one-step habit is the entire routine here. There is no measuring cup, no drawer to fill, and no change to your normal detergent. The formula delivers a fresh, crisp airy scent with 6X longer lasting freshness and odor protection than detergent alone.
That persistence is the real headline. What wins people over more than anything else is simple: the scent itself, which is the aspect owners bring up far and away the most. The second thing they talk about is how well it actually deodorizes a load, and the way it keeps working deep into the following week. The formula packs antioxidants in a fabric deodorizer format, which is the technical way of saying it does not just perfume the cloth — it helps the fabric hold off unwanted smells. There is also a genuinely practical touch in the design: you can keep adjusting how much you use until the scent strength lands where you want it, so a family that hates heavy perfume can dial it back and a gym-bag household can load up.
Keep it honest on the trade-off, though: the one recurring note is that a big, overloaded drum can leave some beads sitting undissolved. That is a loading problem, not a formula problem, and smaller loads settle it. At 1.5 pounds and standing 4.53 x 4.53 x 10.88 inches, the bottle is compact enough to slip onto a laundry shelf next to the detergent, and the fact that it is safe on all fabrics and in all washing machines means you are not gambling on your delicates. Almost everything here points the same direction — it has the highest rating on this list and tens of thousands of people buy it over and over.
The case that keeps it on top
- 6X longer lasting freshness and odor protection for your clothes
- Scent is the thing owners rave about most, by a wide margin, with very strong effectiveness ratings right behind it
- Safe on all fabrics and in all washing machines, so no load is off limits
- Scent strength is adjustable — use less for subtle, more for a gym bag
Where it can let you down
- Heavily overloaded washers can leave a few beads undissolved — use smaller loads
- It freshens and deodorizes, but unlike the Lysol sanitizer it is not built around killing the bacteria themselves
Grab this one: families who want laundry that still smells clean a week after it hits the drawer, with zero extra steps.
Think twice: if your mildew smell is bacterial and lingers even when clothes smell pleasant going in, the bacteria-killer below attacks the root instead of the symptom.
2. Lysol Laundry Sanitizer 90oz
The design detail that separates it from a scent booster is the staying power against bacteria. It keeps odor-causing bacteria from regrowing for up to 10 days or until the garment is worn, so gym clothes stay fresh in the drawer, not just out of the washer. It is also a color-safe bleach alternative at 0% bleach, so it is safe for whites and colors and works effectively in cold water — a real benefit if you are trying to save energy by washing cold. It plays nicely with standard and HE machines, front-load or top-load, and it is gentle enough for delicates, undergarments, baby clothes and bed sheets. On the tougher side of the closet, it is aimed squarely at gym clothes, jerseys, socks and towels with malodor control technology that targets odor molecules directly.
What people keep coming back to is the clean, workhorse quality of the thing — the scent earns the most praise on its review pages, and its sanitizing muscle comes in a close second. It pairs well with oxygen boosters and works across every material in the house. The recurring gripe is worth knowing before you buy: some bottles arrive leaking, so check the seal when the box lands. Lysol ships it in its own leak-resistant box with the cap secured, which helps, but leakage is the most-noted complaint and the honest caveat to plan around. Compared to the Downy beads above, this is a heavier, harder-working product — 5.63 pounds versus 1.5 pounds — and it lives in the rinse cycle rather than the drum, so it demands one extra pour. The new larger 100 mL cap makes measuring quick: one full cap for front-load washers, with top-load guidance on the pack.
Best-for snapshot: households with pets, athletes, or anyone fighting sweat and body odor trapped in synthetic fabrics where bacteria thrive.
The honest trade-off: it works in the rinse cycle, which means a second pour per load and a bottle that occasionally shows up with a leak.
Reach for this if: the smell is in the fibers and you want it gone at the source, not masked.
Look elsewhere if: you want a scent-only freshener with no rinse-cycle step — the Downy beads handle that job with less fuss.
3. Gain Hibiscus Hula Fabric Rinse & Renew, 48 FL OZ
A rinse-cycle helper built for homes where the dogs sleep on everything.
If mildew smell in your house rides in on dog beds and couch covers, this is the pick that earns its keep. Gain Hibiscus Hula Fabric Rinse & Renew is a rinse designed to help wash away odor-causing residues from fabrics — it goes in during the rinse cycle alongside your normal detergent routine. The whole point is that rinse step: it flushes out the residue that plain detergent leaves behind and that bacteria feed on later. It leaves a light, tropical Hibiscus Hula scent on laundry, which is the note that most owners single out first, with overall quality running a close second in what they praise.
The pet-odor performance is the thing the review pages keep circling back to. Buyers report it works “great for pet odors” and that they “use it on the dogs bed covers and they come out smelling so fresh.” That is exactly the use case this fabric rinse is built for, and the formula is suitable for use on most washable fabrics as directed. Since it is a rinse, not a standalone cleaner, it is meant to be used with detergent rather than instead of it — think of it as the finishing step that removes the last of the smell. One useful note from the reviews: it holds up well in hard water, which is often where residue-driven musty smells start in the first place.
Size is where this one flexes. The 48 fl oz bottle gives multiple rinse-and-refresh uses, and it is a physical presence on the shelf: 12.71 x 5.39 x 3.86 inches compared to the Downy beads’ 4.53 x 4.53 x 10.88 inches — a long, low bottle versus a tall, narrow one, so think about which shape actually fits your cabinet. The 4.1-pound weight keeps it steady on a shelf. The recurring wish, and the honest limit here, is that a few owners would like an even larger bottle because they go through it fast in a busy pet household. That is a demand-side complaint rather than a defect, and it says more about how much they use it than about the formula. It is thinner on the shelf than the Lysol sanitizer and less of a heavy lifter, so if your problem is full-on bacterial odor, the sanitizer remains the stronger tool.
Who it suits: pet households that want dog beds, blankets, and couch covers to come out genuinely fresh without a heavy perfume bomb.
Best for: routine odor removal on washable pet fabrics and anything that holds a stubborn smell.
Skip if: you want to attack odor-causing bacteria directly — that is the sanitizer’s job, not a rinse’s.
4. ARM & HAMMER Plus OxiClean Liquid Laundry Detergent
A full-size all-in-one that fights odor and stains in the same capful.
For the household that wants one bottle to do the whole job, this is the answer. ARM & HAMMER Plus OxiClean with Odor Blasters is a 200.2 fl oz liquid laundry detergent in a Fresh Burst Scent, and it is concentrated with 3X odor fighters in every load compared to a leading value detergent. That means the odor-fighting is built into your everyday detergent rather than added as a separate step. It is powered by Odor Blasters, which tackle tough odors like pet odors, damp clothes, sweat, musty towels, and body odor — and triple power action from OxiClean goes after stains at the same time, so odor and stains get handled together.
The scent is what puts it on the map — it is the top thing owners praise, with value for money running second. A user describes opening the closet a week later and finding clothes that “still smell like clean laundry,” with no need for extra scent beads. That is the clean-laundry feeling people are chasing, and it comes from a detergent that doubles as your primary cleaner. It is dermatologist-tested, and owners mention it does not irritate sensitive skin even with the strong Fresh Burst scent. A little goes a long way with one capful, and it handles kitchen towels, bedding, and everyday clothes without a fuss. The Fresh Burst scent is non-overpowering on a normal load but clearly present, which is the balance most people want.
Here is the honest catch, and it is a real one: leakage. Some of these bottles spill in transit, so check the cap and seal the moment it arrives. Buyers who have had no issue love it, and those who got a leaky bottle had a mess — that inconsistency is the main risk with this pick. The other thing to know is a personal one: not everyone likes a strong fragrance, and if that includes you, this one leads with its scent, so the Biz powder below is the unscented route. Weighed against the other picks, this is the most economical per-wash option with the biggest bottle and the most versatile single-product role, since it is a detergent, odor fighter, and stain fighter in one.
Straight read: the best single purchase for a normal family’s weekly wash — it fights musty towels and everyday stains while leaving a long-lived clean scent.
What to watch: bottles occasionally arrive leaking, so inspect the seal on delivery.
Best for: anyone who wants one bottle to handle odor, stains, and freshness without adding rinse-cycle steps.
Not the one if: you need a fragrance-free formula — this pick leads with a strong, lasting scent.
5. Biz Laundry Detergent Powder Unscented 37.5 Ounce
The no-fragrance route for odor that is welded to a stain.
When the smell on a shirt is tied to a stain that has been there for months, springtime grass, dried sweat, or chocolate, this powder is the one that outworks the others on fabric that has been sitting. Biz Laundry Detergent Powder is an unscented stain and odor eliminator built around four stain fighters: a blend of enzymes, powder detergent, oxygen bleach, and whitening agents that work together to target tough stains without damaging fabrics. Because it attacks odors at the source, it leaves fabrics fresh without adding any fragrance of its own — a big deal for anyone who reacts to scent or just wants truly neutral laundry.
What this powder does best is get out the stains that carry the smell with them. The review pages describe it outperforming dedicated stain removers at lifting sweat stains from colored tops, and one user reports it removing urine odor where they had reached for an oxygen cleaner before. It is a booster-style product, so you add it to every load to enhance your detergent’s performance, or you can use it as a pre-soak or a pre-treat paste on the worst offenders. That paste-and-soak method is where the deep odor work happens: wet the stain, work the powder in, leave it for hours, then rewash. It is hard to find in stores, which is why so many people order it in regular batches.
Two things set it apart from the liquid options. First, it is unscented and chlorine-free, so it whitens and brightens without bleach and without masking anything — you get clean, not perfumed. Second, it works in all water temperatures and is safe for both standard and HE machines, and it is color safe, so you are not splitting whites from colors. The honest note is on value: opinions are split, with some owners considering it well worth it and others finding it not the greatest value for the powder you get. That is worth weighing, because if you want pure stain-and-odor power with no fragrance and you are willing to pre-soak, this delivers it; if you want a set-and-forget detergent with a lasting scent, the ARM & HAMMER liquid above is the smoother fit.
Why people keep reordering: it removes stains that carry odor — grass, sweat, chocolate — while leaving absolutely no fragrance behind.
The honest limit: it works best as a pre-soak or paste on tough jobs, which takes time, and the value sizing divides opinion.
Best for: fragrance-sensitive households and anyone fighting odor welded to set-in stains.
Think twice if: you want a one-step pour-and-go detergent with a lasting scent to keep clothes smelling fresh in the drawer.
Know the Specs
Form: Beads, Liquid, or Powder
The form tells you how the product fights odor. Beads are concentrated pellets you toss into the drum and they lean on long-lasting fragrance. Liquids flow through a dispenser or a rinse drawer and can be built to sanitize or to rinse residue away. Powders dissolve in the wash and can be mixed into a paste for pre-soaking a stain before it carries its smell into the load. Match the form to your problem: fragrance for freshness, liquid rinse for residue, powder for tough stains that hold odor.
Where It Goes: Drum, Rinse Cycle, or Dispenser
Placement decides how the product works, and it decides how many steps your laundry day has. Drum products are added before the clothes and need no extra routine. Rinse-cycle additives wait for the final rinse, where a regular detergent has already done its work and only the stubborn residue and bacteria remain — which is why they are the go-to for mildew and musty smells. Dispenser products sit in the main wash and act as your primary detergent. The rinse cycle is the extra step worth knowing about if the smell is the source, not just a stale-scent problem.
Common Questions
Why does my laundry still smell musty after washing?
Can I use a scent booster and a laundry sanitizer in the same load?
Is a laundry sanitizer safe on colors and delicates?
How much Gain Rinse and Renew should I use per load?
What is the difference between deodorizing and sanitizing laundry?
Does Biz powder work as a pre-soak for odor?
Is ARM and HAMMER with Odor Blasters safe for sensitive skin?
How do I stop my towels from smelling sour in the cupboard?
Do these products work in a front-load HE washing machine?
The Bottom Line
For most households, the detergent for mildew smell winner is the Downy Unstopables Scent Booster Beads because it keeps a fresh, crisp scent alive for weeks with a single toss into the drum and no extra steps — the highest-rated pick on this list, backed by the largest base of owners. If the smell is coming from the fibers and you want it attacked at the source, grab the Lysol Laundry Sanitizer, which kills 99.9% of bacteria in the rinse cycle. And for pet households fighting odor on dog beds and blankets, the Gain Hibiscus Hula Fabric Rinse & Renew is the one to reach for. Pair whichever fits with the right method and the musty smell stops coming back.
How we choose
We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.
Sources
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of October 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
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