The problem with letting him stay at your house is...if he decides to do nothing. Then you are left feeling "bad" that you ask him to leave. They (addicts) are really great at making excuses/manipulating.
Sober living is a great idea. Pay the first months rent if you can and that will help you feel supportive.
Recovery is for him. You really can't convince him to do anything different than he wants. Set your boundaries and love him.