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...
Not sure what is going on inside the tank. Sounds like water is hitting the sides. What I feel is very important is to run a few gallons into the tank after closing the valve & leave it there.
Let it slosh around as you drive home or to 'prime the tank' if you will, so that you don't get the dreaded cone.