I've thrown away almost all of my cleaners....
... and have been using "Magic Eraser" from Mr Clean.This stuff cleans anything. However, I have used it sparingly on the smooth gelcoat as I am trying to determine if it scratches. So far it has not. On the non skid, though, Magic Eraser is truly magic.I just used it to clean my dinghy today, and it took dirt off that has been there for 2 years, and made the whole dinghy look like new. My dockmate tried it on some fiberglass stains that oxalic acid did not remove, and the stains came off with a little elbow grease.For a $1.99 give it a try.... Jeff