I overcooked a bag of popcorn (to a crisp)-lots of smoke. The inside cleaned up pretty well...with mild detergent and some Barkeepers Friend. Some parts, such as the gadget that spins the glass tray, are discolored. Also, the greyish silver 3x4 plate attached to the right sid of the inside cabinet is sploched, licked a scorched white shirt....is this dangerous? Or is it just a cosmetic thin. Can I still use this microwave?