i found that an overnight soak in oxyclean brought all mine to the surface like magic, the only issue i have is i have 3 diffrent grades of sandpaper at my house, 2500, 596, and 180, and i'm not touching my pipe with 180. i think if i had a 300, i would have been able to buff it all out and get it to looks brand new. as it is, the 596 took out a LOT of it, but it took a LONG time. the 2500 grit made it look like glass though, so while it has a little bit of cloud to it, you can only tell in direct sunlight and only if you look for it