Most all Alabama coins are dirty so if I think I have something it gets a quick 5 min soak in acetone to remove the surface gunk. Maineman once told me that too long in acetone is not a good thing and I have seen some of my coins that soaked overnight seem to somewhat change color in a negative way. I think about 15 minutes in acetone is going to do all the good it's gonna do. I never tried Verdicare and I'm sure it's a good product. But, I have come to really like Mineral Oil and I don't think it hurts the coin at all to let soak indefinitely. I have seen Mineral Oil remove some pretty bad gunk.