mayer, first of all you should rinse your glasses immediately after using them ;-) don't be like me and leave them till the next morning....:-) Anyhow I found the best way of cleaning anything that stains my glasses as well as my ceramic coffee mugs (heavy coffee drinker) I use the cheapest denture cleaning tablet (dollar store brand)and let them dissolve inside the decanter or even the coffeepot. Hope this helps and makes sense.