I always get interesting looks when I'm walking across the campground carrying the bottom half of our Porta Potti. They can tell it's heavy going to the bathroom area, but much lighter coming back. I do the same thing with our portable gray water container, dumping in the toilet, unless there is a separate drain area for it. On the
UHaul, the gray water line extends our the left bottom of the trailer and we hook up a Coleman water jug with a short length of hose to screw on to the outlet pipe. When we do full hook-ups, I run a length of garden hose from the outlet pipe to the ground sewer pipe. The only trick is getting the hose to run downhill as much as possible or the water won't drain out of the sinks.