I'd heard other members talking about this method and was always wondering if it was worth the trouble. Well IT IS. Last fall I applied a good coat of "Nu-Finish" wax. Well I just got done washing the trl for the first time this spring, and the black streaks disappered as if they weren't even there! Guess the 3 hours I spent last fall waxing was worth it. Now to do the spring waxing. Being retired now, the time is there for me to do the extra things around the house I wasn't able to do before.