To clean anything glass, ceramic, or metal, use denture cleaner! It gets rid of dusty gunk and gets rid of cooking stains. Totally using this on everything covered in coal dust in Paul's kitchen! ps. the blogs also say that alka seltzer works for all of the same stuff. Not sure which is cheaper...probably the alka seltzer?
HOW TO REMOVE STAINS FROM ANTIQUE CHINA Pour enough 40% peroxide into a plastic tub to submerge the china (use gloves and protective glasses) and put the lid on the tub. It should take about a fortnight for bad stains. Check daily. Once the stain has disappeared, rinse china thoroughly and soak for two or three hours in clean, warm water. DID IT.