He should eat it often with his meals. A teaspoon of 50-50 powdered charcoal and honey will help sober up a drunk person. People who regularly eat good nourishing food are less likely to crave stimulants or addictive substances. Especially eat raw fruits, vegetables, and nuts. Meat eating will bring back the craving for alcohol, so quit meat.
Slippery elm is also good to drink while going off alcohol.
Quassia chips help destroy the taste for liquor. Put 1 teaspoon in a cup of boiled water, steep a half hour, covered. Take a swallow every 2 hours. Stay with someone, so you will not be tempted to go out and buy more of the cursed stuff. The Neutral Wet Sheet Pack is excellent for alcoholic delirium.