I built a clear black tank and tested the Sewer Solution

It doesn't matter how you drain it, there will be a lot of stuff left in if you don't use a rinser. I use a clear extension to watch the rinsing water and it takes several drain, close, rinse, fill, drain cycles to get ALL of the stuff out. I can look down into my tank from the top with a mirror and inspect it. I also use a spray wand from the top every few trips. I wish my gray tank had a rinser.