I usually just boil the rims to remove tyres - works perfectly and you've got de-tyred rims in 30 minutes.
I've found the best container to boil them in is an old 9" aluminium pie tin - they're nice and wide so you can easily fit 6 or 8 rims in at once. (and you're unlikely to annoy anyone by using nice cooking pots)
Basically, cut away as much of the tyre as you can and salvage the foams (unless you've used schumacher blue foams which inevitably disintegrate into a fine powder!
).
Next put about 2cms of water in the pie tin and boil the rims for 15 minutes.
Turn the rims over and boil for another 15 minutes.
The tire remains will pop right off and any superglue residue will become a brittle yellow crust that you can easily flake off with a hobby knife.
Done!
NB - some types of plastics do not handle the heat well - I've experienced cracking around the inner rims with yellow Tamiya rims and Ballistic Buggy rims.
I've boiled Associated, Losi, Proline, and JC Racing Fastraxx rims with no problems at all.
I agree that acetone is a good way to go - but for instant gratification boiling works for me.
Cheers,
Ty