Oh, Lovelife, I wish you immense strength and confidence. Taking him and leaving him at the Salvation Army will be such a test. Once I took my son to The Rescue Mission. He was loaded, had spent the day tearing through the woods somewhere, dripping sweat and passing out when he finally arrived on my doorstep. He begged to be allowed to shower and just sleep . No chance. The next morning I called The Mission and he was gone. For many days I didn't know where he was and was frantic. He finally showed up and was rescued by his girlfriend. Again another soft place to land and someone to enable his addiction.
I hope you are able to stick to your guns and let this man take care of himself and his addiction. Remember you did not cause it and you can't cure it. Good luck and be sure to let me know how it goes. From this mother's heart to yours.