Our first camper was a previously owned unit, and I don't know how well the previous owner did at cleaning the black waste tank. The sensor on ours seemed to indicate it was quarter full or more all the time, even when we were certain it was empty. So I used this Power Blue Waste Digester to try to do a better job at cleaning the tank without having to get too physical with it. It is apparently pretty strong, as the recommended dosage seemed fairly small for a 40G tank. So I put it in when closing up and let it sit for the next two weeks. When I came back and flushed the tank out, the sensor was properly reading empty and the last bit of water coming out was certainly much cleaner than it was previously. Another similar treatment after that, and it was looking great. Ever since then, I always use it regularly.Now with a new camper, I regularly use a little in my black tank all the time and the water always looks good and never have had any odor issues. I even always add a tiny bit to the sinks to help keep them very clean, in case any food particles, fats, oils, or such are hanging around too long in the grey tanks.
Rating: [5 of 5 Stars!]