have you had a sit down with him and all wrote him letters to the point of:
"We loved your tone before you got mixed up with that flanger. We want our pre-flange tone back." Do they have a 12-step program for overdone effects?
Seriously, if he's just started using the thing he'll probably chill out once the novelty has worm off. I listened to the track and while it was a little intense, I've heard a lot worse effect abuse and have probably been guilty of it myself. When I first got my talkbox I overused it. Then after a month or so I thought to myself, "does Cumberland Blues really need a talkbox in it?" Now I use it once a night maybe twice but never more than that and on songs where it is more fitting. I've got a buddy who's a great player and plays a lot of funk-rock stuff. He has a whole slew of pedals that he painted over so you can't tell what they are (he can't even remember) and sets 'em up turns the knobs to random places and when the mood strikes he turns one on and away he goes. Sometimes it works . . . sometimes not.