Paint = Nitromorse (just paint the goo on, leave for a while, then use scrunched up newspaper or similar to wipe it off, burns if you get it on your skin)
Anodised = Caustic soda (can get in most hardware stores, dissolve it in water, dip bike part in and leave for a few mins, voila. Do it outside though its very horrible stuff)
EDIT: TOO SLOW