Almost, believe me when I tell you that I understand how you feel. This ow thing is hard to get your mind around.
Here's the thing, yes, in DR it says that the non cheating spouse needs for the other to stop seeing the ow. But that is only if the cheating spouse is willing to do that. I dont think your h is just yet.
Look, he will see her or not see her, talk to her or not. And no amount of you asking him not to, telling him not to, is going to stop that. He could promise you til next week, not going to matter. He is ready when he is ready.
What are you going to do about it?
I can tell you that pushing him and making him promise is not going to get you the desired result.
So, you really need to let this die its own natural death or it will come back to bite you in the a@@.
Try not to give this woman any headspace because really she is not worth it. She is a sympton of whatever it is is going on with your h. She matters not.
This is his journey. He needs to take it and you need to continue on yours.