a hoedown piss is when you go to the bathroom and don't want to wash your hands after, so, instead of touching your cock, you pull down your boxers and rest your balls on the elastic of your boxers, allowing your wiener to rest there, pointing towards the toilet. you then place both hands on the front of your boxers and proceed to squat up and down like you are at a country hoe down.
when finished urinating, one can shake by simply gripping the elastic of the boxers with the thumbs and middle fingers and simply pull up and down on the elastic, shaking your wiener and flinging piss off in all directions.
most appropriately performed outdoors or in bathrooms at fast food restaurants
I had to punch doug in the back of the head cuz I caught him hoe-down pissing in our bathroom last weekend.
(Bill and Steve's conversation after Bill, who was shitting in the stall, and Steve, who was pissing in the urinal beside the stall, leave an Arby's bathroom together and sit down to eat)
Steve: (reaching in for one of Bill's fries) Can I have a fry?
Bill: you can eat shit and die. I never saw you wash your hands before we left the washroom.
Steve: dude, its fine, I hoe-down pissed
Bill: alright then , yes, you may have a fry. but only one. or ill skull fuck you.
Bill and Steve: (highfiving) hoedown piss!