I don't normally answer questions from non readers but... All you need to get the class clean is one of those nylon scrub pads (the flat 1/4 thick x 4 inches x 6 inches no soap on it just plain nylon) and some white vinegar and elbow grease. Apply the vinegar with a rag and let it soak in for about 10 min then scrub, rinse and repeat as needed. Rinse thoroughly Robert