I think what you are trying to do, although well intentioned, is very dangerous. If your son is drinking enough to have withdrawal symptoms to be medically safe you should probably take him to a detox and not try and do this at "home". This is not a forum for medical advice. Just know that severe alcohol detox really, REALLY, needs to be MD supervised and monitored. What are going to do if he has a seizure in a hotel room? Can you stay awake 24 hours a day to make sure he's safe? Perhaps the real question is why was the decision made to NOT go to a treatment center? What's the thought behind that?
Good luck. You have my prayers....