Heh, works! At work I just rinse my coffee cup out with tap water. I like the patina that evolves.
Bleach only changes the color of the stain to white. It’s still there, delivering foul old oils to your new tea.
I use an empty net onion bag as a scouring pad to go in and scrub them out. Save your net bags, tie a few of them together for a great all-purpose scrubber, they last ten times as long as store-bought scrubbers.
I’ve found that if I give the inside of the cup/mug a quick scrub with the wet tea bag after I finish my tea and before I put it in the sink, that helps keep hard stains from accumulating. Scrub lightly, not too hard, or the tea bag will break. Of course, this isn’t possible if I’m having a pot of loose-leaf.
I also keep one or two old toothbrushes near the kitchen sink for any kind of small-spot scrubbing. They’re good for getting at the inside of the tea-pot spout or that thin line of stain that develops under the spout when you pour, but toothbrushes do not work well if you’re trying to clean the bottom of a mug.
i find the patina soothing and identifying.
Do not put bleach in the dishwasher. Bad idea. Your owner’s manual should specifically state not to do this. The word “genius” in the subject is presumably being used ironically.
Bar Keepers Friend is the answer for really difficult stains. I rarely have to resort to it. Just a soaped up scrubbing sponge usually does it.
Unless your dishwasher has stainless steel in it you’re wrong: How to clean your dishwasher
^ This is my method.