Originally Posted by dbriceno
Mary Kate On Off is the marine version you can get at a marine store. Use gloves.
I use Mary Kate On and OFF as well. I've used the regular and the gel version. The regular works much better IMHO. It's primary ingredient is.......you guessed it, Oxalic acid.
Gloves are a must, I use goggles to be safe, you don't want that stuff splashing in your eyes. I wet down the hull, then use a rag to wipe it on gently. It looks like it's not doing anything when you wipe it on, that is ok. Just start wiping it on and move along. You'll look back after a few minutes and any discoloration is gone. If you're using elbow grease you're doing it wrong.