As a smoker I can say that the stink is one of the worst things about this bad habit. There really is no way to get rid of the stench unless you stop smoking. Yes, you can douse yourself with cologne, but I think that increases the smelliness. Listerine for the odors that come out of the mouth works.
But, most of the odors you are smelling originate from the clothes, and skin (mainly hands, and face).
There's not much that can be done unless he stops smoking. Which can be a very hard habit to break.