Lee, Whangarei.

Try Chux Magic Eraser Hard Surface Cleaner to clean stains from cups. There are eight disposable blocks in the packet and they can be bought at the supermarket.  You can also buy them as a block and cut to the required size. It’s amazing also for cleaning around light switches, removing crayon, scuff marks off floors, etc – just wet and lightly rub! You can use each piece more than once.