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The short version: this is a thick gel for the black mold stains that build up on washing machine door seals, grout lines, and caulk. You run a bead of it along the stain, leave it for a few hours (overnight is easiest), then rinse or wipe it off. No scrubbing. Sprays run off vertical surfaces in seconds. The gel stays put the whole time it works.
#1 Best Seller ACTIVE Mold Stain Remover, 7 fl oz
Seal & Grout · 7 fl oz

Mold Stain Remover Gel

Cleans and deodorizes seals, grout, and caulk.
$19.95 $24.95 Save 20%
A fix, not a replacement.
Gasket replacement serviceup to $660
Bathroom regrouting$300–$1,000
Caulking service call$200–$500
ACTIVE Mold Stain Remover$19.95
How you use it
  1. Apply. Run a bead of gel directly onto the stained seal, grout line, or caulk. It is thick enough to hold on vertical surfaces.
  2. Wait. Leave it alone for a few hours, or just go to bed. The gel keeps working the entire time it is in contact with the stain.
  3. Rinse. Wipe or rinse the gel away. Stains that have been building up for years can take a second application.
Gel applied along a washing machine door gasket
Where it works
Washer door seals Tile grout Shower caulk Toilet rims Faucet bases Appliance seals
Where it doesn't
Torn or crumbling rubber

The gel removes stains from intact seals. If the rubber itself is shredded or falling apart, it needs replacing, not cleaning.

The moisture behind it

Stains return if the surface never dries out. Fix the leak or ventilation, then use the gel on what got left behind.

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Before and after
Before and after results: washer seals, tile grout, shower caulking, toilet rim, appliance seals, faucet caulking
Washing machine door seal before and after the gel
Tile grout before and after the gel
Pairs with
ACTIVE Washing Machine Cleaner tablets
Smell coming from inside the machine, not just the seal? The gel handles the gasket. The deep-clean tablets break down residue and hidden buildup in the drum. The two are often used together. Get the Washer Cleaner on Amazon — $19.95 →
5M+ Bottles sold
19,405 5-star reviews
a Get it on Amazon — $19.95
Available at Amazon
Ships free with Prime · Sold by ACTIVE