I appreciate you guys providing info on the black/grey tank flush. But that brings me to my next question...what is a 'third valve'? What does it do? How does it work?
I obviously live a very sheltered life, as I never heard of such before!
U295 serch for "3rd valve installation " in the serch box and you will find many posts on the subject. Will explain it better than I can.
The Camco Flush King is simply a portable third valve with a way to backflow the tanks with additional water for improved clean out.
The third valve is permanently attached to drain, to allow you to use grey water to add or balance to black. You will still need an additional way to add additional water for the best cleanout.
Try this thread for a general discussion that contains more good links:
Waste tanks combine? (http://www.foreforums.com/index.php?topic=34310)
I did mine.
Recent third dump valve installations (split from another topic) (http://www.foreforums.com/index.php?topic=25056.msg197677#msg197677)