I've heard about their meth-induced obsessive-compulsive habbits, but I have no idea why they exhibit some of the behaviors they do. Then again, I've never been a meth addict, so I guess I have trouble relating.
I don't seem to see anything specifically related to bleach and methamphetamine addiction, however one could posit the psychological effects of meth lead to such errant behavior.
I dunno. I keep asking myself what I'd do if I thought that I had an infestation of insects crawling under my skin... however, I seem to find some difficulty in arriving at an answer for that specific dilemma.