Originally Posted by VinceU
The built in flush gives a lighter rinse to most areas of the tank but not all. Its best used with a fill and flush also.
I had been using my tank flush simply with the valve open and letting it run for five minutes after the black tank was drained. The last time I dumped, thanks to this technique being mentioned almost daily here, I tried the fill and flush method after a five minute wash. The good members here really know what they are talking about. When I opened the tank, lots of nasty stuff came out. Thought I should take a moment and thank the people here for talking about this flush and fill technique.