How about propofol? It needs to be monitored, as the Michael Jackson case shows. But, I think I got it for a colonoscopy. They told me to think of something like the beach. Then I looked at them and asked if we were done and why my throat felt scratchy all of a sudden. "Yes, and we had to use a little suction."
It was instant lights out and lights back on. No fog. And no atmospheric pollution.