I disagree that it's a "time" issue for most parents. What I see is dysfunctional, ignorant parents who are either too stupid, too pre occupied with themselves or too damn lazy to teach manners to their children!
It's always been my Number one issue with my son, and I must have at least two or three parents remark to me each week about what a kind and polite boy he is!
It's very rewarding but we work on it every single day!
That's wonderful about your son. I see many parents reluctant to correct their children, like they're afraid of being seen as mean - or they just don't seem to care.
Good for you, same here. My kids chew with their mouths closed too, and the grown man sitting across from me at Chilis the other day could have taken a few lessons.