Description: Meme of wide-eyed innocent Spongebob on left with caption "coffee stains" juxtaposed again muscular and angry Spongebob on the right with the caption "TEA STAINS".
Sorry if memes aren't welcome here. Just have been experiencing this since my partner drinks morning coffee as opposed to my morning tea, but her vessels can basically just be rinsed out. Whereas removing tea stains actually takes some elbow grease.
I'm on an orange pekoe or yorkshire (bagged), followed by ginger-turmeric green tease (loose) kick at the moment.
I use a melamine sponge to remove them, the surface is actually a powerful abrasive, so be careful with that, it might take gilding or decoration right off as well. Last resort when my favorite mugs look tatty. One brand name in the US is "Magic Eraser".
I've settled into giving them a good soak and then just using elbow grease with a dish sponge I don't mind discolouring.
Thanks for the tips though. Good to know if I have a truly intractable job!
I can just tell I'm about to rotate this word into my active vocabulary, until someone comments on my overusing it.
I'm honored to hear that you might adopt it, it's a common word here.