A Dutch Gas Mask is the act of inserting a rubber hose or similar apparatus into one's anus while attaching the other end to one's nose & mouth with an oxygen mask or similar apparatus to enjoy their own odour & gaseous emissions. Mainly practiced by fetishists.
To hell with the dutch oven, I totally did the dutch gas mask last night, it was epic!
A Dutch Gas-Mask is when a male, who needs to fart, places his cupped hand on his ass, farts into his hand and clenches his fist, catching the stink inside.
He then finds one of his guy friends and then quickly opens his fist right against there nose, releasing a whole lot of toxic fumes right into the unlucky guys nostrils.
*Guy 1 thinks to himself I need to fart, while Guy 2, is looking away, so he decides to do a Dutch Gas-Mask, and farts in to his hand, and clenches.*
Guy 1: Hey, Dude, smell that?
Guy 2: *Turns* What?
Guy 1: This!*Unclenches fist under Guy 2's nostrils, and he begins a coughing fit while Guy 1 Laughs*