I use the flusher if at a CG and have time. A couple of times a year I use my home made flusher that goes down the toilet. It aims a strong stream of pressure and really does the best job. I have my wife watch the tank level indicator and blast them directly until they read empty.
This year I'm going to try another idea. I have installed a third dump valve at the sewer hose connection so after I dump black, I can close the new valve and allow the grey to flow backward into the black tank. I figure I'll get 15 to 30 gallons in there form my 60 gallon grey tank.
Then close the grey (which will still be half full) and dump the black again.
Then finally dump the grey.
I hope to see a lot more "stuff" coming out with this approach.