I've never used one, and my house is on it's own septic system so wouldn't want to clog that up. We do have 5 little kids living at my house, plus two 18 yr olds, so I assume a lot of stuff that won't dissolve well are being flushed down the shitter already. Will probably have to have the septic tank pumped out at some point, but never have yet in 18 yrs since I built the house.