A old hotrod/chopper thing for de rusting chrome bits was make loose aluminum foil balls and dip in a bowl of Coke-A-Cola. The coke is acidic but not as harsh as chems commonly used for derusting and the aluminum foil is softer than all the surrounding material except the rust.
A lot of elbow grease involved in this way though. After you're done a quick wipe down with water hand dry and the wipe with WD-40.
