[Neverhome]

I use Dawn dish washing liquid. I read on a forum that it helps clean the tank sensors of grease and debris. As an aside, most sensors stop working very quickly and are difficult to get working again. I have heard there are new ones that attach to the outside of the tank and work well, but are pricey. Can't say for sure if Dawn does clean the sensors, but I don't think it will hurt the valves and may in fact keep them clean too. Works in the porcelain bowl though. When your toilet starts to "Burp" when you flush, it is time to dump the tank.