We had black mold on the caulking around the shower. I tried brushing it with vinegar, baking soda and bleach using a toothbrush. None of those made any difference at all. I ordered some RMR-86 and what a difference, I noticed a huge improvement within 15-30 minutes. Probably about 50% of the mold was gone. I treated it 3 more times over the next few days and there is now no more mold and I could not be happier with this product. A small brush worked better for me than the spray to apply the product. Now I'm going to use some RMR-141 to see if we can keep the mold from coming back.

Product worked great but the spray bottle nozzle doesn’t work after the first use so you better use the whole bottle the first time. 👎

Really does remove the mold stains. Important aspect of property management to have this available.

We have been using this for years and are just as happy with it now as we were the first time we used it. It does exactly what it's designed to do.