Several reviewers also recommend this for stainless-steel coffee pots! All you have to do is fill your bottle with warm water, drop a single tablet in, and let it fizz the gunk away. The tablet dissolves completely, so once you dump out the water, you can use your bottle again right away! Check out BuzzFeed’s full write-up on Bottle Bright.
Promising review: “In all my years of attempting to remove the tea stains from my large white ceramic mug and metal tumblers, I have never come across anything as effective as this product; it is simply amazing (I wish I took before & after photos). I filled the mug with boiled water, dropped in a Bottle Bright cleaning tablet and let it do its magic. Within one hour the tea stains from the metal tumbler were lifted, literally, and floating. My white ceramic mug took a bit longer but the result was also absolutely perfect, as if both of these drinking containers were brand-new.” —Bruce P. Starr
Get a pack of 12 tablets from Amazon for $8.