The green goo caused by coin folders, and soft poly coin folders can be cleaned with Carbon Tet (Tetracloride), if you can find it. You don't have to rub, just dip it in the liquid and slush it around some, then rinse it off. Die Makers used to use it to clean tools. I don't know how hard it is find in the open market. There is a coin company in Sidney, Ohio that markets it under a different name, but it is really just Carbon Tet.