Originally Posted by spud
so...the black water cleanout..
Is it just an access into the tank? I was thinking it had a hose of some sort that would wash the sidewalls for you when you hooked up to it and turned on the water.
should I run extra hose into that access port?
Not really sure what you are referencing here.
I've not seen a "BW Cleanout" on a trailer in the same sense that your stick built house has a cleanout on the sewer line that you can access to insert a sewer rooter or snake.
The Black Tank flush fixture that I've seen on trailers is female hose fixture where you attach a pressurized hose. It pumps water into the BW tank, but inside the tank is a spinning head that squirts high pressure water jets in all directions, with the intent of scrubbing the inside of the BW tank, rinsing toilet paper off the walls and bottom, helping to break up any large lumps or clogs of #2, and sending them down the BW drain through the drain hose (stinky slinky).
Often times, RV dump stations may not have a male fixture on the end of the rinse hose at the BW dump. You may have to bring your own hose (not your FW hose) to screw onto the BW rinse water supply line and then to your trailer's Black tank flush hose fixture.