I read to never leave both grey and black valves open at same time to prevent gas from going back in
wing_zealot wrote:
They're making it way to complicated. Hook up slinky and drain the black tank. While the tank is draining hook up the hose to the black tank flush. When the black tank is done draining, leave the black tank valve open and drain the grey tank. While the grey tank is draining turn on the water to the black tank flush. Flush the black tank for about 2 minutes ±. Turn off the water to the black tank flush and disconnect hose. When both tanks are done draining close both valves, put on the cover, stow slinky, and leave. Total time - less then 10 minutes (probably closer to 7). Total time wasted on nonsense flushing - None. Total time forcing other people to wait in line for your OCD - None.
