Hull Cleaning with Toilet Bowl Cleaner
 

for the first time ever, i was fortunate enough to have my boat in the water for pretty much the entire season this year. i docked it right after ice-out and she remained there until the end of august. it was fantastic having my boat at the ready all season long! however, it also meant that i would have to deal with the dreaded bottom grime that develops when a boat spends the season in the water. being a working stiff, i try to do much of my own work myself to save money so i thought i'd give this a go. did some searching and found many products and remedies for this, but none of them i had on hand, except for this. i used the cleaner pictured, put it in a spray bottle and sprayed it on the hull. after letting it sit for 8 or 10 minutes, i then hit it with the pressure washer. here are the results.. not perfectly clean (my hull is painted aluminum, off white/tan color), i can still see a but of a "hue" or discoloration, but it's pretty darn clean. clean enough for me anyway, and super cheap! have a look..

Wow.....not bad and nice tip.
I've been using On Off bottom cleaner but I'll give Lysol a try

the important thing is the hydrochloric acid content. i think this has 9.5%, but you may be able to find another brand with a higher percentage. this is just what i had on-hand. and for what it's worth, i used 4 bottles on a 24ft boat. i probably could've used 5 but only had 4. i think the wife buys it at the dollar store for $2/bottle. which reminds me, i need to replace them... she was a little pissed that i used all the toilet cleaner!

I use Acid Magic, Aubuchon carries it as well as Amazon. If you have an aluminum trailer, cover it. Spray it on walk away for 10 minutes and it will be clean. Hose it off and you're done!!

You should keep acid cleaners off of all trailers, not just aluminum; they do a number on galvanized and painted trailers too... Stuff is awesome at cleaning gel coat, but nasty on metal. For that matter, keep it away from your propulsion system too...