phlegm in the throat is usually a sign of sinus drainage. Tell him to take a really hot shower everyday and to attempt to hack it up because the steam will help loosen the stuff in his throat and chest. Also, if possible, go to the doctor to make sure its not an infection of some sort, because a sinus infection can cause excess phlegm. also avoid smoking. I smoke and I know I get congested and all kinds of crap built up in my chest and throat.