My experience is that aluminum foil works pretty well if the rust is just on the chrome and hasn't actually bonded with it. The down side is that if the rust is deep enough in the chrome that aluminum foil won't get it off then rubbing with aluminum foil is likely to make it worse. Of course, worse is a relative term in that case because pretty much nothing is going to bring it back to its original shiny goodness.

This is a fork I experimented on recently. The leg on the left of the picture was scrubbed with foil and then wrapped in Evapo-Rust soaked paper towels. The leg on the right of the picture was just soaked in Evapo-Rust soaked paper towels.



Neither side looks like new, but the foil took off a bit more of the chrome plating (which for the record was fairly cheap chrome plating to begin with). If you look closely you can make out some pitting (in addition to the bare spots) on the "better" side. I think that's the best you're going to get if the rust has taken hold.