He already knows what you want. He is not a dummy. He knows what he needs to do, if he wants to get straight, he will, for him, not you. As selfish as addiction is, so is recovery. He is not good for you or the children until he makes up his mind to give up the drugs, and start a sound recovery program.
Even if he starts a program, there is no way to know if he will stick to it, and there should be no relationship for at least a year, a year of soberity, a year working a program, and not using.
He will always be an addict, it's just a matter of whether he is active or not.
What are you trying to accomplish by all of this? What is your pay off?
I agree with OOAL,neither of you are willing to change. And, both of you are playing a game,one that your children will suffer for.
I can keep posting to you until the cows come in, and if nothing changes, nothing changes.
I too, wish you the best.