Noob to TDPRI. Recently became the new (only 2nd) owner of a Dean Markley RM-80-DR. The original owner never took it out of the house and the thing looks literally like it just came off the showroom floor. However a few of the pots are scratchy. Is there any special way or cleaner to use to clean the pots? I'm comfortable taking things apart but would like to know what to do once I get there. Thx.