We couldn't let either of our kids come home - it was a set up for them to start using again.
It wasn't good for us, but because we were codependents, we ignored that part. So how about this... it wasn't good for THEM. It was almost a sure way to ensure my kids WOULD screw up.
So they both went to Oxford House (google the term). They needed 30 days clean and since both went directly from rehab, that wasn't so much an issue. It was a great way for my immature, non-working kids to figure out how to live on their own as adults.
And at 23... your son is truly an adult.
I wish you well. (((hugs)))