Both of us being former bethelites, I agree with New boy....it's probably the best thing you could hope for at this point (if he really wants to stay a JW that is).
It's important to plant some seeds.....tell him that when he gets there he will see some things that are not suppose to be at bethel....drinking, girls, partying, etc.(Hey why did I leave exactly? Just kidding). So every time he sees stuff like that going on, he will be reminded of what YOU told him.
I've seen ALOT of guys show up at bethel thinking that bethelites are nearly perfect and poop out little pink twinkies when they go....when he sees what the real bethel is like, his whole view of the organization will change....MAKE SURE HE HAS SOMEONE TO TURN TO AND TALK ABOUT THIS WITH. Gymbob