I was a part of an intervention 20 years ago (before I became a candidate for one myself). It was done by a professional. We had my friend's family, boss, pastor, etc. all lined up. He was either going to rehab or he was going to lose his job, place to live, etc. He went to rehab and with the exception of a 4 day relapse 7 years into it, has been sober for 20 years. Interventions can work.