Yes, it will help chewing. But it won't work if he doesn't want to quit.
I used an herbal alternative to quit dipping (although I didn't have a strong dipping addiction, like I did smoking), called "smoky mountain chew" it's basically just grass, but it tastes very similar to wintergreen snuff. I mixed it half and half at first, and then gradually weaned myself by cutting in more and more of the herbal product and less and less actual dip. Then I switched to gum.
All this is pointless of course, if he doesn't want to quit.