As anyone of you would know, ceramic coffee cup or mug can get stained easily if you often drink coffee or tea with it. There is usually a round ring of stain found at the level of the coffee or tea when you filled up your cup or mug. I have tried using regular dish soap and hard scrubber to remove those stain located on the inner side of the cup or mug and it doesn't help much. At first i thought that was the regular design that came with the new cup when i last bought it, but when i went back to the store to check if the other cups have it, they don't have the round ring stain in its inner side. What is the best and fastest way to remove those stains as i am a regular coffee and tea drinker and i do not want to have to do it the hard way. The problem is that even the hard way of scrubbing with dish soap does not remove those stains in the cup.