Posted this as a comment in another thread from a guy who got deepthroated by a heroin addict. Cleaned up and added details:

Similar experience, I was 18 or 19 and driving through my grandparents old neighborhood. The area had a couple known crack houses and had declined over the years. I was approached by a lady at a stop sign. In retrospect, she was probably in her 30s but could have passed for 50; thin but not bad looking for a lady I thought was 50. I was young and more optimistic about the world and people in general so when she asked for $5, I gave it to her. And she offered...

So she got in and we pulled into a side street and she pulled my cock out. She stroked me a few times then leaned down and licked it before taking me into her mouth. I cupped one of her shriveled breasts as she deep throated me until I came. I was young and pretty inexperienced at the time and probably barely lasted a minute, but it was a glorious, dirty, lust-filled minute. Would pay $5 for crackhead throat again.

I've got lots of stories so maybe I'll write some more up.