remove larger stains, like coffee or tea from cups
After years of use, tableware can develop larger stains beneath the crazing (the tiny cracks in the surface of the glaze) from coffee, tea, or food. To dissolve the stains and really brighten up the pieces, you’ll need 3% hydrogen peroxide and a plastic tub with a lid.
Place your pieces inside the tub and pour in enough peroxide so that everything is submerged — you may have to buy several bottles. Cover with the lid. Let them soak for about 2 days, and then carefully remove each piece and place it in direct sunlight to dry. Once everything is completely dry, hand wash to clean off the peroxide.