Derived from 'skitching' (skate hitching, i.e. grabbing onto a car for momentum while skateboarding or rollerblading) and the 'wagon' metaphor for sobriety (on the wagon, fall off the wagon, etc).
"I haven't had so much as an O'Doul's in days. If these goddamn inspectors aren't out of here by Monday, I'm gonna lose my fuckin' mind."
"Wanna smell my flask? There's nothing in it, but-"
*grab* *SSSSSNNNNNNIF* "Oooohhh..."