Put them in a whittman, library of coins, or dansco album. Leave them there for a decade or so. Viola -- toned coins (hopefully!).
Time is the only natural way to tone a coin the way it should be. As far as Im concerned, trying to tone a coin yourself with a torch, oven, microwave, tanning bed or whatever else you can find that disperses heat is just as bad as taking a wire brush across it. Of course, thats just my opinion.
