If your RV has a tank rinse it has a built in back check.
I hook a non drinking hose to the flush. Open the black tank valve let it drain until it runs clear. A clear elbow is needed for this.
At this point I close the black tank valve and set a timer for 6 minutes on my phone and place it in my pocket.
Timer goes off I open valve let it run clear then repeat the 6 minute fill and drain. All the while letting the tank flush run. Close the valve and count to 60 then shot water off to flush. Go inside add chemical to toilet fill bowl with water and flush. Now you are done and following this you will never have the dreaded POOP PYRAMID!
I usually do this the day before we travel so the tank will have something to slosh around while traveling. I also make sure there is water in the grey tank when traveling.
