Just looking for some suggestions on cleaning rotomolded plastic boats. I noticed on my tempest that there are some black smudges and such that don't come off with general water and some rubbing. I didn't want to just start using any grease cutting kitchen stuff without checking to see what the general consensus is on cleaning. I have 303 and use it during the summer to bring the shine back to the plastic but I feel like this stuff just glosses over the dirt. Thanks!