There are several threads that detail this:
http://www.coolminiornot.com/forums/viewthread.php?tid=2089
http://www.coolminiornot.com/forums/viewthread.php?tid=1272
http://www.coolminiornot.com/forums/viewthread.php?tid=1684
http://www.coolminiornot.com/forums/viewthread.php?tid=802
http://www.coolminiornot.com/forums/viewthread.php?tid=798
http://www.coolminiornot.com/forums/viewthread.php?tid=60
As you can see, this is one of our most asked questions. My answer is to make a combination of pinesol and ammonia. It eats the sealer but does not harm plastic, and turns the paint into a bunch of gunk that can be scraped off. I just bought a brass wire brush, which is softer that pewter, so I don\'t think it\'ll scratch it but I\'ll have to try that when I actually need to strip something.
Oh, and in case you need to know the answer to the second most widely asked question, NMM is Non Metallic Metals, the art of using opaque paints to simulate metal surfaces.
