Fasinating that both of you are freaking out because he's at a homeless shelter as opposed to his next shot, being the one that kills him. And once again, he is flying the "Rescue Me" flag.
Time -outs at a homeless shelter are becoming increasingly common in rehabs when a patient seeks drugs, especially those patients who come from enabling home situations.
I think it's a terrific idea, kind of a preview for how his life is going to turn out, if he chooses to continue using drugs.
Odds are he is safer at the homeless shelter than he is, back in the comfort and safety of his home, while doing his DOC.
Worse thing for him, right now, would probably be for a well meaning friend or family memmber to wire him money or to rescue him.
Give him the dignity of realizing the consequences of his choices.