The sexual act of partially inserting ones penis into a female's (or male's if that's the way you swing) nostril, and emptying your bladder. Because of the anatomy of the sinus cavity, pee will come shooting out the other nostril... thus cleaning out the sinus of any impurities, more or less. Like the Neti Pot.
Shannon: what the helll do you think you are doing? get your penis away from my nose!
Andy: ever heard of the Neti Pot, or Neti Squeeze?
Shannon: yes, but what does that... oh no you don't!!!
Andy: oh yes I do... hold on tight, shut your eyes, here comes the Neti Pee. SHAZAAAAM!!