It's called 'Krud Kutter Graffiti Remover.' If you're like me, you might be a bit...frugal. (Or just a cheap bum. Also good, right? I like honesty sometimes.) Now, metal models are a pain in the butt in terms of customization (and often pinning, for that matter) but it is very easy to remove the paint from them. It involves a glass you'll never drink out of again, and some acetone.
In fairness, if you're willing to take time and be both patient and quick, you can dunk plastic models in acetone and scrub them real quick, but this is sometimes known as Asking For Trouble, for if you're too long the plastic gets infirm.
Now, the the directions say to spray the surface and let it sit, but I found it more useful to simply pour some of the Krud Kutter out (...man, I feel like an ork when I type it out...) and cut it with a little water to make it go further. It's safe to soak plastic stuff in overnight, though it probably works faster. Afterwards, attack it with the good ol' toothbrush. You might need to soak it twice, but no more, and it works a WHOLE LOT FASTER than the standby of Simple Green.
The only downside? It is a little more expensive than Simple Green, but I believe you can get more actual WORK out of the Krud Kutter (WAARGH!) per unit volume (since the paint softens up, but doesn't necessarily flake off and darken/pollute the solution like I've had with Simple Green).
Anyways, that's your quarterly painting advice from the Raptor. Enjoy.
Also, it doesn't have NEARLY the distinct smell that Simple Green does.