If it was done in Corpus Christi, then it was conducted by the US Navy at the Naval Air Station. They train new pilots there.
It would be a tough trick to do since it is so cold at 35000 feet, plus fly the plane, plus do the breathing trick, plus having a decompression at 35000 feet would be exciting enough event all by it's self.
As a side note I read that blood will boil in your body at the 60000 feet level with no pressurization. I think it happened to an F-104 pilot whose engine stalled out at that level.
