I spent a few years flying a DC6 firebombing. The mid cabin emergency door was hinged on the forward side. If you needed a mid flight pee you just popped the lock and the door floated open a few inches with a nice vacuum at the opening. Whip it out and the stream went into the gap and disappeared with nothing on the airframe. Worked great until the, rather heavy and not very fit, other crew member decided to go for wizz when we were coming home on top at 16,000 ft in an area with a 15,000 ft MSA. He did not take a walk around bottle and passed out by the emergency door. Now we operated this as a 2 crew airplane with no autopilot so this was not a good situation. Fortunately it was smooth air and the good old 6 was wonderfully stable so I was able to run back with the walk around bottle slam it on his face and then run back to my seat with the airplane still flying along nice and straight.
The guy was pissed at me because I hurt his nose during my very enthusiast application of the O2 mask.
