Lilbit, I think you are posting hoping for a bit of a consultation with Dr. Shoshanna.
Well you don't say how long you have been married & how long it's been since he was in contact w/ her--I'd think the longer time that has gone by, the less likelihood that he will contact her again.
Whether he was brainwashed or not, I wonder if he has taken responsibility of his life, deal with the reasons why he has taken up with this girl, addressed how his upbringing help create and formed his values and behaviors that may not be healthy.
Has he gotten therapy?
Your DH could have a codependent personality.
I don't think it had anything to do with brainwashing. I think he. like other men I have been friends with, was addicted to this girl. He was with her at a formative time in his life and lived with her as a family. Some of the nicest men I have known have been inextricably drawn to that girl that abuses them and is forever hard to hold. They could go out with the nicest girls you would ever want to meet, but they were always drawn back to that one that treated them like crap. The more abuse she heaps on the harder he tries to please her. It doesn' t sound rational because it really isn't rational. That is why I call it an addiction. Some guys have such bad self esteem that they wouldn't want to belong to a club that would have them as a member, so to speak.