Yuck. Too much information! Lol.My TT has a built in black tank flush. I do not use it. First, it takes a lot more time at the dump station. Second, you can flood your trailer if you get distracted.
I simply use plenty of water in the black tank and dont dump it until it's close to full. I follow up the black tank dump with a close to full gray tank dump when possible.
My TT's black tank is very clean. I know for a fact, because I have had my arm in it and looked all around in it with a mirror recently...I was trying to locate a dropped flashlight.
Thank you, I’m going to try the Rhino Blaster I guess. Another person said they run a hose into the toilet before they close it up but I would be to scared the hose would come out and make a mess. In my opinion EVERY pop up should come with some kind of back flush system built so you don’t have to raise it up at the dump station and make everyone mad because it takes so long LOLIf it's a standard black tank connection, the Valterra Hydroflush works great. We use it on our small TT, as long as there's a spigot to hook up the hose. It has the advantage of rinsing the tanks (we have a gray tank too, although it doesn't really reach that because of bends in the pipe) and the sewer hose too. After dumping, I close the valves so that it rinses the intersection of the pipes, then (after closing the outermost valve, rinses the sewer hose well. Once in a while, we find a dump site that we can't use it, but we usually can do so.
Camco also has one: https://www.amazon.com/Camco-Rhino-Blaster-Sewer-Rinser/dp/B00T36KRS2/ref=sr_1_3?crid=1SQ112QQ6VW0Y&dchild=1&keywords=camco+sewer+hose+rinser&qid=1623695766&sprefix=camco+sewer,aps,244&sr=8-3