We got stuck in a 5-hour traffic stop due to a fatal accident on an expressway. While having an RV is a blessing in situations like this (we were able to watch TV and see why we were stopped!) - no one ever asked to use our bathroom. When we finally DID get moving, we noticed a lot of wet spots on the pavement from "tire checks", however.....
Depending on the circumstances, I might let a mom with a child, or an elderly woman use ours (assuming it's not winterized). Guys?? Nope - they already have the advantage of "every shrub is a urinal". And when you think of it from the other viewpoint - I think most people would not be comfortable going into a stranger's "home" to use the bathroom. WE know RVers are good folks, but millions of people watched "Breaking Bad"....LOL!