Corrosion/stains won't wash off. They are on the coin permantly unless you dip them and ruin them. Best advice, don't clean a coin. If the coin is/was BU, then touching it up ruins the value. On circulated coin caked with grease around the devices, soaking it in mineral oil will help loosen it, but ONLY on circulated coins. It will not remove corrosion or stains. Only grime around the devices. To remove corrosion is to remove part of the surface and ruins the coin to a collector/grader.




















