It's most commonly found cut with all kinds of dirty crap, most of the time you have no idea what you're putting in your arm or nose, and has a nasty habit of reducing people to hollow shells of their former selves, completely disconnected from rationale or emotion, replaced with that same kind of sweaty-socks paranoia that comes from routine abuse of DRIs...
the lifestyle it tends to inpsire is not what one would usually call 'clean'. Heh, even saying that though, I've got this one mate who enjoys getting completely tweaked on pink rock, taking apart everything in his house he can find and meticulously cleaning it with fine brushes, then putting it back togetehr again. Clocks, electronics, cupboards... You'll know if he's come down or run out early because you'll find escape wheels and transistors in the carpet for days until he scores again.