Originally Posted by dpolen
I used the MaryKate On/Off stuff for the first time this year (had used Starbrite and West Marine stuff previously). I was VERY pleased with the results, best cleaner I've ever used. My boat sits in the lake all summer, this stuff took all the water spots and algae off with very limited scrubbing. $14.99 at West Marine right now, worth every penny. Get yourself a mask and rubber gloves before using it, its strong stuff.
On-Off is a very effective acid cleaner. I used it for years until I switched to Slimey Grimey (more dilute). I have found that to do just as good a job as On-Off without the need for protective gear, damage to the trailer, damage to aluminum (windshield frame), or etching of the concrete.