Believe it or not....
I am assuming you are talking about the rub rail as opposed to toe rail. If not, disregard my comments. On our 33.5 we have a black rubber rub rail. We tried lots of things and found the best thing to be a silicone based vinyl/rubber dressing made by Amway to last the longest. It lasted a whole season whereas we found the Armor All and other formulas only lasted a month or so (especially if in salt water and bringing the rail under occasionally.Don't call me though, I am not a distributor.Doug