On plated steel wheels, the best thing I've found is a soap pad, the steel wool kind used on pots and pans.
I wet the soap pad and hold it lightly against the inner surface of the rim while spinning it, gradually working it in toward the spokes. When the spokes grab the soap pad and fling it, or I start jamming a finger against the spokes, I'll repeat the process on the opposite side. Soon there will be only a narrow track of rust in the spoke path, to be dealt with tediously using soap pad and sore fingers.
Two points in favor: Quick results, and the soap deposits a nice wax-like film on the rim, which buffs off with a dry cloth leaving a nice lustre.
Two points against: Some claim that steel wool can embed in the chrome, promoting new rust. Also, you WILL swear like a bad person when you stub your finger.