Yet the water will still rise up into the hose up to the water level in the tub....then when you lift it out, the remaining water in the hose can trickle back inside the 1st Stage. In another chat; an Atomic user says he called Atomic HO & they said that it is best to soak it pressurised
How deep are you dunking your second stage underwater for the water pressure to reach your first stage? I have owned atomic regulators and used them as my primary regulators since circa 1997. I own several of them and have never had an issue with water intrusion, and I never rinse them pressurized. They are always clean inside without any traces of water intrusion. I have a bucket I use to rinse regulators (and computers). I put the second stage lower than the first stage in the bucket, and that's it.