Since I have tried just about everything to clean coin, due to the fact that I dig em outta the ground. I used olive oil at first but now just use hydorgen peroxide. The olive oil is very hard to get off of the coin after it has been soaked. Stays with it for a long time. Plus doesn't really work very well, for my situations anyway. My two cents
Boiling in distilled water will do it (remove olive oil) as well. Little globules of oil will float to the surface during the process. Ben
good info I know we have all been told not to clean coins, but there are some times it just can't hurt. This thread has been very informative about gentle ways to revove the gunk. the gunk covered coins are the prime candidates for cleaning/restoration.:smile