I read a posting on another forum in which they purchased a 1/2" MIP to 3/4" Male Garden Hose adapter (Watts A-663), removed the outdoor shower head, connected the shower head to the BT flush inlet, and pumped in the pink stuff. I'm planning on doing that for both the BT Flush and the city water connection. For the BT Flush, I'm guessing I won't be able to pressurize the line, but it will at least force out any water that could be sitting in low points of the hose. Hopefully that will be enough.
2013 Jayco JayFlight 26BH
2013 Toyota Tacoma SR5 w/Towing Package
4-Point Equal-i-zer Hitch
Prodigy P2 Brake Controller