Welcome to SR,
Know that detox is just the beginning, as horrible as it is thats the easy part, the hard part is staying clean and chances are he can't do this alone, does he know about Narcotics Annonymous? It would be a good thing for him to check out.
Now you've raised some serious questions about how you can deal with all this. Please go check out Naranon or Alanon meetings, they will give you the tools you need to help you help yourself. Because you can't help him, only he can. But you can help yourself.
Check it out,
Teggie