Re: Over-zealous office cleaners...
get the tannin stains off the tea-drinkers' cups
What! Remove the years-worth of flavouring? Nooooooooo!
Almost as bad as my mum taking a wire-wool scourer to my favourite wok[1] on time she visited on the basis that 'it looked dirty'.
I had to season it all over again and cook more chinese meals for several months before it got back to being properly coated.
(Although I do have to wash my coffee mug - the ladies in the coffee shop at work tell me off if it isn't clean..)
[1] A proper Ken Hom mild steel wok. None of yer teflon-coated rubbish. I actually have two of them - one for cooking meat and the other for rice/vegetable dishes that I use for cooking if my vegetarian niece comes over.