[angst_ridden]

I volunteered at one of the homeless organizations in downtown LA for a while. It's a safety consideration that most shelters require residents to be clean (although some of the shelters are more militant about that than others).

However, just saying "gotta be clean to be in this shelter" doesn't solve the problem. There need to be adequate treatment programs available for drug and alcohol rehab. Those programs have been cut, and private centers cost far more than most unhoused people can afford.

Furthermore, there's a positive feedback loop that needs breaking. The experience of being unhoused can lead to people escaping into drug use, just as excessive drug use can lead to homelessness.