It clings to tile, meaning it'll STAY PUT, killing mold and mildew and keeping it from reappearing later down the road.
Promising review: "I CANNOT emphasize enough that this stuff works MAGIC!!!!!!!!!!!!!!! I wish I had taken before photos, because when I say magic, I mean UTTER WITCHCRAFT. The caulking around my tub was staining moldy, but a little hit of this and it was GLOWING WHITE like we had just recaulked. I recommended it to my aunt, whose house was built in the 1970s so her tub caulking stains were over 40 years in the making, and she was going to pay someone to come in to strip the caulk and do it over new. I told her no need- just use some of this stuff! Worked like witchcraft AGAIN!!!! Her caulking is also glowing white now, and she's recommending it to HER friends now!!! This stuff is so good, you'll recommend it to everyone you know. No caulking stains are too deep for this!!!!!!" —Amazon Customer
Get it from Amazon for $13.99.