Question: My cups are stained with brown tea and coffee stains?
Answer: Many people use harsh abrasives to try to clean their coffee stains and then find that the stains keep coming back. Be careful about harsh abrasives, they can actually pit and scar the surfaces increasing the odds of the coffee stains returning. Instead try baking soda on a sponge to gently remove the coffee stains. You can also use some oxygen bleaches on coffee stains. Check the directions to be sure that the oxygen bleach is safe for the surface you're cleaning.