Excellent Vendor; product okay, but maybe not for the truly blackened pot....
In a quest to help my parents find a good substitute for DipIt, I tried this product.  Their old Corningware percolator was midnight black inside, and Concentrated Coffee Pot Cleaner lightened that staining....somewhat; at least they can now barely make out the numbers (indicating no. of cups) inside the pot, but after two applications, the pot is still pretty dark - not the spanking white that they used to get with DipIt.  I'm giving three stars, however, because 1) I think this product will work for users who don't wait until their coffee pots are tar-colored on the inside; and 2) the incredibly thoughtful and polite followup email I received from the seller, Impressa Products.  When they were informed that the product hadn't worked for us, not only did they apologize for our troubles, but they issued a full refund.  I recommend this product for folks who clean out their coffee pots on a regular basis, and heartily recommend Impressa Products for their excellent customer service.  I've checked out their Amazon storefront and will definitely be shopping there in the future
Rating: 3 stars