The upper echelon of being a complete douche bag. Not the useful, clean, vinegary fluid that goes in, but the useless, cottage cheesy, foul smelling mucousy substance that comes out.
That dudemarcus is a fuckin tool bag. Yeah dawg, he's a total bag of doosh waste.
A troublemaking little skank who gets into all kinds of mischeif. Usually hyperactive and sneaky, not rare to resemble a rodent of some sort (i.e. rat, mouse, meerkat, prarie dog, ect.). A complete klutz who ruins any situation as to be sneaky.
When someone is acting like so much of a dooshbag, you could float them face down on a river, grab a paddle, jump on their back, and paddle away.
Person 1-Goddammit dude, did you see Justin Bieber's ungratefulness when he was graciously given with that water bottle by means of air mail to his forehead?
Person 2-I know man, he looked thirsty! He has no reason to bitch about that, what a doosh canoe!