We have traveled almost exclusively in a travel trailer for the last 20 or so years. All of the features on several different models have been used extensively. Never have we ruined a toilet. How would one do that? All you have to do is wash the thing. Run lots of water through the tank when you dump. Leave a couple of gallons of fresh water in the tank and add a digester and deodorizer to it and go. If we have dumped for the last time before storage I don't #2 it, but that is the only time. Even your arm pits will stink if they're not washed.