[JandC]

There was a video circulating either on this forum or another, can't recall exactly where (getting old). They had a holding tank out of a unit and were testing several ways to rinse it out. If I recall the built-in flush valve didn't work any better than any other method.

I have been using my Flush King for the past few months and will probably continue. It seems to rinse my black tank quicker. In addition, every so often I close the grays one at a time and back flush them also several times. Since doing this I never get any type of smell from sinks or my black tank.

If my built-in black tank flush quit working I wouldn't spend a dime or my money or 5 minutes of my time fixing it. I think my Flush King cost me around $35.00 and I can see how it is working.