If you want to experiment
Acetone can do no damage to metal because it is a solvent and it cannot dissolve metals
( This does not mean the coin will look better afterwards ! )
Acetone will however damage the surface of your fridge if you use it to clean off water resistant marker ink because it tries to dissolve the paint or plastic of any appliance or the platisizer from PVC etc or grease from your fingers if you put your fingers in it they will go white drying and be bone dry for some time (not a good idea )