Add an extra valve down line
Just thinking off the top of my head( I know that can be dangerous).
One of my holding tank valves is under the slide and when the slide is out, you can only get to it by crawling under. Has anyone taken one of the add-on valves and placed it on the other end of the hose and leave the valve on the trailer open(grey tank)? Just Thinking out-loud.
2019 Rockwood 2608BSD 2019 F250 4x4 6.2
“Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming "Wow! What a Ride!” - Hunter S. Thompson, The Proud Highway: Saga of a Desperate Southern Gentleman, 1955-1967