This is something I've offered informally before. Is it something you'd pay for?
Getting the incentives right is tricky. Money is often not going to be the right incentive here.
I don't think its true that they can necessarily make more programming themselves than I can afford to pay them either. Remember, I am not wanting to hire someone full time, but for only a few hours a week. If I have to pay multiple hours of wages for an hour of high quality coaching, that is perfectly fine with me.