Sadly, this never worked with my son. Sometimes it worked for a while, but in the end the outcome was always the same...he used, he acted out, he broke our boundaries and had to leave.
I often maintain here that "we" are not their only option, we're not even a good one. A sober living house would be better, or even sharing a place with someone from AA or NA with strong recovery, or finding a small, affordable place of their own. It's a start.
Also, the Salvation Army Rehab programs are free and are quite good programs. As with most programs, the success rate is relative to the resident's willingness to get clean and stay clean.
Good luck, I hope whatever you choose works for you.
Hugs