I found the review of tank flushing systems pretty interesting.
I do wish he included the wand which is sort of a "tornado" type fitting for hand use. I use one of those plastic thingys to hold the toilet valve open and then insert the wand end (on a quick hose end fitting which allows me to rotate the wand without kinking the hose) below the toilet valve, turn on the water and slowly rotate the wand while lowering the wand until it meets the floor. Sort of a more involved "tornado" type fitting process but it avoids what I see as the hassle of installing the tornado fitting.
Testing Tank Flushing Systems in the Clear RV Black Tank!
You may want skip this if you're a fanboy of the Sewer Solution, at least as it relates to cleaning the tank. It's still hard to beat when it comes to discharging uphill or over a distance.