No lock and key is not the treatment.There must be some reason which causes him to drink alcohol.Some time depression,mental pressure causes start of this habit.we must treat him in a humanitarian way.If we can realise him that this habit is not good then he stop his habit from his own.
Next Steps
1.Behave friendly with him.
2.morning walk,join yoga class,gym etc
3.Try to get rid off those friends who are alvohol addicted.
4.Search the actual cause of this habit.