Tea stain removal

Tried clothes washing powder? But I expect that won't work either now....

Two-pound hammer, perhaps? :-(

David

Make up a 10-20% solution of bleach (I've used Parazone at times)and soak the cups in it over night.

Bicarbonate of Soda. use neat, with just a little water as per scouring powder.

It sounds really as if glaze has failed after all those years, so even if you can get them clean, the chances are they won't stay that way for long. Although modern dish washing powders are much better, some of the older ones that you probably used a few years ago used to be very abrasive.

You may find one of the oxygen bleaching additives designed for boosting laundry detergent performance will do the trick.

caustic soda.

if tat doesn't work - or handwasing with a scourer, get new mugs.

I've occasionally wondered if cleaning with very harsh caustics (caustic soda), ... Followed by reheating the pottery up to glazing temps would work.

Hi,

If strong household bleach fails try something containing oxalic acid, like 'Barkeepers Friend' or decking cleaner(!)

Using liquid dishwasher detergent instead of tablets may reduce the problem with any new cups, AFAIK tablets contain a mild abrasive.

cheers, Pete.