Works great with a little elbow grease
When I bought this stuff, I thought it would basically just dissolve the coffee/tea stains from the metal cups we use, which were pretty much brown. I even let it sit undiluted in a cup for like an hour, and it still didn't take the stains out.<br /><br />Turns out it requires a bit of scrubbing....not much, but to my surprise the stains came right off after a few minutes of scrubbing, and all of the cups look brand new now.
Rating: 5 stars