Maybe he should quit focusing on weaning himself off porn and focus instead on beginning to make financial contributions to the household.

If he starts working, he will not have an opportunity to nap during the day.

Without that opportunity, he would have to sleep for more hours at night.

With the need to sleep for more hours at night will come the necessity to limit the time he watches porn.

So if his goal is to wean himself off porn, his obtaining gainful daytime employment would help him reach that goal as a collateral benefit, without placing demands on you.

Problem solved?