Your the chemist so if you say so. But methanol, petroleum distillates, and toluene are all bad for coins to the best of my knowledge. And all leave residues that you then have to use some other chemical to remove them.
Sorry, Doug, but no residue "if they are pure". Even acetone can leave a residue if it is contaminated. BTW Toluene is essentially the same as Xylene. A way for @ZoidMeister to check to see if his lacquer thinner is uncontaminated is to put some on a mirror and let it evaporate. Residue means DON'T USE IT.
We'll give that a shot tonight. The three "non valuable" coins have already been in the drink for a few days. I didn't look at them last night, was painting a closet. Hopefully I'll get a chance to take a peek in there to see "what's left" of them. Z