I LOVE Earl Grey teas. BUT!.....

How does one remove the stain they leave? I have it in all my tea
cups, some which are collectible Otagiri's. I know that elbo grease,
a dobi pad, and some dish detergent will do the job, but some of my
Otagiri's have gold around the top edge and I don't like using
abrasives on that thin layer of gold. Any suggestions?

TIA
nb