Coca-Cola......that's some strong stuff! Or, you can try some Tang...yeah, the same orange drink that NASA sent up with their astronauts. When my wife and I were first married, we lived in a small rental house that had very hard well-water...stained everything! Couldn't wash clothes in it, and barely could stand to bathe in it. DEFINITELY didn't drink it! We had a small, portable dishwasher that hooked up to the kitchen faucet. After several uses with the hard water, it became extremely stained inside...the white lining was practically muddy looking. We tried everything to clean it,, even tried scraping with a razor, but the inside was more like it was permanently stained. We had someone recommend putting Tang in, instead of dishwashing powder and running it without dishes. So, we poured us a couple of adult beverages, pulled up a couple chairs, put in the Tang, turned it on and watched it run for the next hour or so. When it finished, it was just as clean and sparkling inside as the day we bought it! I do not drink that stuff anymore.......