An illegal narcotic anesthesia derived from corpses (we're all goo, right?)
This knock out juice would require someone to harvest it from corpses. The amount of corpses to fill a vial would vary, based on: state of corpse (how decayed), And the skills of the graverobber. (Based on medical stuffs)
This full container would be refined down to a vial by a chemist. Like other drugs, the skills of the chemist will increase the potency (knockout length, it should be, max, like half what legit knock out juice does) And decrease ADDICTION.
This juice should be very, addictive. It's essentially a refined narcotic in the streets super stronger then it should be, but with a super short half-life. Which just BREEDS addiction irl. I think, at the maxest of skills, it should have a 10% addiction rate.
This addiction would push the 'chrome addiction' gameplay to it's next level, imho. That chomie is lookin' to rip a fucker, and get his next hit of Z, better be careful.