Hi Snelling, why can't he detox elsewhere? Usually the advice is they come home once they've had at least a year's sobriety and are working a program.
You know him best. Do you think he really wants to detox, or is he using it as an excuse for somewhere to lay his head?
BTW - they use because they're addicts. It's a common excuse that someone else is 'making' them use, because it passes the blame away from them. Don't fall for it for 1 second.