Please be careful using your kids as a way to motivate unless you know with 100% certainty. His driving them home from school each day may also be an invitation to drink and drive w/your kid in the car. Take it from a mom with experience on that.
I am not saying it works or does not, just saying that the kids come first and when you have children with an addict there is a whole new set of problems to watch for.
Not trying at all to be snarky, just saying be very careful.