Yep - you gotta rinse the coins in fresh H2O afterwards and
remember not to drink the leftover Coke cause you
could get copper poisoning or something - umm- maybe
Seriously though, as Hopalong said I would leave them untouched
as they may be more valuable as is. If you do want to clean them up I
would contact a coin dealer first of all and ask what is the best way to do so.