use drano crystals in cold water let soak for about 10 minutes and that nasty stuff is gone. then you can polish to a high shine. i rinse them off with water and scrub a little to get the black crud off with a 3m scotch brite pad then polish and looks awsome. easiest method i ever used being everthing i put together that is the first thing thatcomes off the nasty coloring of anodize i personally like the metal lokk!!!!!!!!!

good luck
steve