I've read the entire thread and I did not see advice on showing the female guest how to use the RV toilet, i.e., not having to use a lot of water if no solids are involved, in order to conserve on water, and putting the TP in a provided trash can in plastic, again to conserve on the tank. And . . . above all else, nothing else goes in the tank, like feminine products or even flushable wipes! A pre lesson will save in a lot of future hassle. When our daughter in law came camping with us for the first time in the RV, I gave her a lesson on how to use it and even did the same with the 4 and 5 year old.