PCP - 'angel dust' in the city, 'killer weed' or 'green' in the 'burbs, came through DC in about 1974 or so. I recall being en experienced marijuana head at age 12 and getting a hold of my first PCP joint. Smoked it just like it was reefer, and got real fuckin' sick. Ten or twenty big fat tokes, and I was bad off for many hours. After a few dozen similar experiences I was off it for life - for some reason I always smoked too much or smoked it when I was already drunk, and always ended up violently ill.
In 2012 there are still multiple open-air marts here for PCP, usually it's dipped cigarettes instead of sprayed-on reefer or parsley or mint like it used to be. i know a few long term 'green beans', and can assure the board that it's never gone away.