Using the FWT and pump isn't fool proof either if you don't turn the pump off when leaving the RV.True story,.......
I recall a couple years ago, a TT right next to me had water running out of it, and I could hear the water pump running. I went to the neighbor on the other side, asked if they knew these people,....answer was no, so then I tried the door, and to my surprise the door was not locked. Thinking someone mite be inside,... that something had happened to them,....left water overflowing somehow, I asked the neighbor if he would go in w/ me to check,.....to turn off the WP switch if nothing else, which we did. No one inside,.....very strange !
Later I found the owner, by himself, said he had done some plumming couple days before, wasn't very concerned about water damage,.....and never even say thanks for turning the switch off.
At least he didn't threaten to sue me for entering his RV w/o permission !:)