ouch.... I made the mistake of soaking a cruddy penny (stinking/zinkin/linkn) in salt and vinegar solution. I wanted to see what happened if left in that juice over night! It was interesting to see the all of Lincoln's face become removable from the disk of zink...I also hydrogen peroxided a 1902 V nickel - ok I didn't kill it but I don't think it helped take the dirt off of it with out removing some of the woman's head on the front. disappointing finding something old (finally) and botching the clean up operation. I think for now on, I'm just going to use acetone (nail polish remover) and just fluffy Q-tips -only as both products aren't expensive for cleaning coins.
The don't clean coins mantra is something I'd go with if I could only find coins I can make a date out on and know it's worth something- I'd never hit a Merc 1916-D with a tooth brush, but when I find stuff that is crusty and trashed -well I don't' have much hope that they are going to be VF and be worth something (that's the only way I'd clean a coin, knowing it's worthless to begin with.)
anyhow man - keep the coin for yourself in your own collection, and enjoy it. just remind yourself before you do it again on your next find...