Um, I don't know whether or not it's actually possible. Sceloporus, it's when you breath in through your nose, while simultaneously breathing out with your mouth so the air circulates like that.
I've heard of people who play the digeridoo, and apparently they can do it. It's funny, a lot of aboriginals used to do it to pass breathalyser tests lol, until the cops found out and started holding their noses lol
Good luck