Just a thought, but on my chrome rear bmx rim, the winter grit salt and water killled the chrome plating and made it all flake off. Is there not some similar thing you could do to get this affect? Bath full of grit salt?
Haha.

bead blasting should be able to knock the chrome off, you less at risk than the people with weedy alu frames.

dunk it in some acid for a while, it will strip the chrome off...
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if your happy to go for a ghetto look for a while then take all the chrome back with some wet and dry paper, this will allow water to permiate through the chrome as chrome plating is porous and the steel will rust behind the chrome lifting it off.

may take a while and be patchy tho.