Stained cups and saucers

Hey guys, recently purchased set of hand painted cups and saucers. They have what appears to be water stains on several of the pieces. What is your advice on the best way to bleach or otherwise remove stains?
Thanks in advance

 

A method I have used with some success is to make a paste of baking soda with a little water and rub with a paper towel; this is quite gentle and often will remove stains safely and easily; it is a very mild abrasive and has some chemical action also. Others may have other suggestions.

 

Thanks so much for the info. Will give it a try tonite.

 

Thanks. Will try it. Love your neck scarf!

 

Barkeepers Friend and Magic Eraser, too.

 

If the staining is inside the cup away from the decoration, pour in some hydrogen peroxide and cover with waxed paper (plastic wrap and paint not always mixing too well) It'll bleach out the tea stains.

 

Actually, the entire surface is stained. Trying to upload photos. Obviously, not successfully. . They were found outdoors and had been in the rain and weather. I believe they are water stains. Have tried 40 volume peroxide from the beauty supply. Worked about 50% but took almost a month and still has some of the staining. I know not to use chlorine bleach. Help!
Be still my heart, it worked!