I only use the black tank flush when the camper is home. My house water pressure is 80psi. Maybe the RV system can handle this pressure - and maybe not. I know I don't want to be screwing around with any black tank issues. I use a regulator.
I disagree that this is an open-ended system. Those little sprinkler openings by themselves will build pressure as they are restricting flow.
2015 Shamrock 231KSS, Oyster shell
2016 Chev Silverado LT Z71 Ext. Cab, 4x4, 5.3L V/8
Reese Straight Line WDH, 2000W Honda Gen.
2 Old Town kayaks & 2 Boston Terriers - Zoey/Gonzo
Lar & Ruth
55 nights camping in 2015, 45 in 2016