How can I get rid of stains inside cups?

I use bleach spray cleaner. Spray it on the inside of the cup for a little while. Then I wash them with dish soap and rinse thoroughly.

I would try soaking with white vinegar.

Baking soda and white vinegar if I want to scrub them. If not I soak them in boiling water with a bit of bleach, but make sure to rinse them well.

Put some white vinegar into the cup and let it soak for a little while then wash it as normal. The stains should be gone.

I got rid of some using Brillo pads,

Sounds like Maluse has the answer.

Bleach works to remove those stain. You have to wash very well after you used the bleach. If you do not like bleach vinegar and salt.

Have you tried bleach?

Great question. I not only have fragile teacups, I also have china teapots with their spouts. I wonder if the spout innards are all gunked up?

When my cups get stained, I just throw them away. they don't cost too much

I work in a kitchen. The stains are mainly from tannins in tea and coffee. We normally soak all cups and tea/coffee pots in detanner before washing them. If you don't want to use a chemical just use a sponge like the one in the picture it gets rid of the stains quickly. Do it every time you use the cup and you won't have any stains.

I am using a dishwashing liquid for this issue. One drop of that dishwashing liquid would do the task. Name of the dishwashing liquid, Pril.

I try vinegar, then bleach if that doesn't work.