409 won't work on enamel, but it works well on acrylics most of the time.
Castrol Super Clean is the way to go IMO. Pour it out of the bottle into a tray / bowl / something large enough to hold your RR body, and then let it soak for a while. How long "A While" is depends on how thick the paint is, but it usually works in a couple of hours. You may need to use a toothbrush on stubborn areas.
Once its off, wash the model THOROUGHLY as there will be a slippery film on it from the Super Clean. Also avoid prolonged exposure to your hands.
You can pour the Super Clean back in the bottle and reuse it again later.