FIND a piece of pottery or glass that has stains to be removed or needs cleaned. If you have an old piece of pottery or dinnerware that has stains or rust, or a piece of glass that has sediment or calcium deposit, it can be cleaned. Let's deal with the porcelain, pottery or dinnerware first.
PURCHASE the products if you do not have them on hand. Rust can be removed with a product called Barkeeper's Friend or any product that has OXALIC ACID. If you do not have ZUD or a similar product in your kitchen cabinet, it should be available at your local drug store or grocery store. Whatever you use must contain the magic ingredient, oxalic acid. White vinegar and cooktop cleaner are also great products for cleaning antiques and collectibles or vintage dinnerware you use.
SPRINKLE the oxalic acid on to the rust spot and add just enough water to make a paste. Rub it around on the rusty spot and leave it just long enough for it to work. When you wipe it off, you can SEE rust going away. This product also works for the metal marks caused from Corning Ware and similar cookware rubbing against metal in the dishwasher. These show up as gray skids on the white body of the Corning.
USE white vinegar to remove buildup from standing water. For GLASS, use white vinegar full strength and let it sit over night. The next morning, the calcium or buildup from leaving water sit in a glass vase is gone. If there is something in the bottom of a bud vase that you cannot get to, put RICE in the container with some liquid and swish it around. The rice works as a mild abrasive. Oxalic acid will remove rust from glass, too, although rust on glass is not as common as on dinnerware.
GIVE UP on sick glass. Sick glass cannot be remedied. This is glass that has discoloration from the dishwasher, and it is actually etched. Some other glass stains can be removed with a paste of COOKTOP CLEANER wiped around the inside. Most cooktop cleaners have alcohol and detergents, and for some reason this works with clear glass to remove stains.
With these products and a little time, you can remove stains, rust and residue from vintage porcelain, pottery and glass.