i have been using nail polish remover to strip the chrome. it works but you need quite a bit of it (cos it evaporates quickly). it also stinks like hell and can damage furniture like table tops if you spill it...
might have to give Easy Off Bam or Dawn Power Dissolver a go instead.

i bought a whole bunch of those Kosutte Gin-san powders and have been messing around with different things trying to get the technique right.

on white plastic, the chrome has a yellowy tint depending on the viewing angle.
on black and also blue plastic, it looks really dark.
on flat plastic, the chrome is pretty dull so you definitely need glossy plastic.

logically, i would assume that plastic with a glossy grey coat should give the best results so i'll give it a go next time. otherwise, i'll revert to applying more coats on the gloss black plastic and hopefully it will make it lighter.