Quoted for truth.
Brake fluid is the king of paint removers. It's cheap, easily available at all auto parts stores, mega marts and even gas stations. It is safe on plastic models and metal ones too. It is non flammable and doesn't stink too bad. You can also reuse it for more models as it doesn't evaporate.
I use a size appropriate container to place the model in and fill it with brake fluid. Wait a few days and scrub with a toothbrush. repeat until satisfactory results. Wash with soap and water and rinse. Easy.
Just make sure you use this stuff in a garage or appropriate location as brake fluid in your house isn't too smart. It will destroy carpet and flooring. Be smart were you use it!