My son uses auto wax on his ladders and yes, he buffs them too. He's pretty picky, but he's a CATV installer and wants his truck to look sharp. I can't say that I'd blame him. He also says that having a smooth surface makes them a lot easier to extend when handling the ladder by himself.
I can speak from experience that UV exposure will eventually deteriorate them if something isn't done. I have a 28' one that literally had a foot break off due to UV rot. You should take care of them before this happens.
"But the guy at Home Depot said it would work."