I wasn't paying attention while closing the insert door a few minutes ago and brushed my elbow up against the exterior glass. Didn't even notice anything other than foul odor of burning plastic. My fleece has now left a hardened residue on the outside of the glass. Any advice on what my next steps are here? I tried wet paper towels, rotating to new ones as they got hot, but no luck. Shut her down and try alcohol/scraping when she's cool?