White/greyish mold in a cup I had a cup of hot chocolate maybe a few months ago and completely forgot about it and its grown a thick layer of white/greyish mold can i clean and reuse it or should i just throw it out?
Assuming that the cup is made from ceramic or glass there will not be any problem in cleaning and reusing it. 

There may be an issue with how things react with metal over time but I sincerely doubt it.