I was of the impression that you could fill the bowl with as much water as you wished for the flush. Though we never actually used it, we did have a 28 foot RV with a V 10 Ford (2011). It seemed like there was a hose and sprayer there to add water, but details are sketchy!
Originally Posted by Doug Ambrisko
Yes, a regular RV toilet with house hold flange. As others say, RV's are designed to dump into a tank then and then dump the tank. They don't flush with much water compared to home toilets. So you might end up with things plugging. We had that issue when we had a smaller pipe and didn't when we went to a larger pipe.