the act of clearing one nostril by blowing out through it with great force while pinching the other nostril shut. this results in a massive evacualtion of anything that happens to be in the nostril.
specifically, the AUSTRALIAN snot rocket is performed after one has recieved an Australian Booger Blaster, and the resulting "rocket" is composed of both mucas and semen.
man 1: "last night i gave my wife an Australian Booger Blaster!"
man 2: "nice dude!"
man 1: "yeah, you'd think that, but then she blew an Australian Snot Rocket all over my chest."
man 2: "ew dude, you shoulda got the hell outta the way!"
man 1: "it's cool, i got the dog to lick it off."
man 2: "wow, there is something really wrong with you man."