Hope someone can set my mind at ease. I have a 2014 Arctic Fox 5'er and have had it out a couple of times. When I use the Black Tank Flush I'm not sure if it's working. I can hear the water running...
Put a clear plastic adapter on the end of the RV's sewer pipe so you can see how clear the fluid is. It helps to close the black tank valve and allow the flushing water to enter the tank without draining out. I usually run it for about 30 seconds. Then open the valve and flush out any extra `stuff'. Repeat as necessary. The flush stream doesn't clean everything out.