Fool, sorry, missed your question re the couple.
FOR THE LOVE OF ALL THINGS HOLY, DON'T DO IT!
These people will not be trained to withstand a Category A abuser! He'll tell them all manner of shit, reel them in and they will end up siding with HIM. He will then turn UP the abuse against you and he'll have allies!
That is the worst case scenario.
best case is that they do see through him and refuse to be manipulated, and he'll get pissy about it and you'll get the fall out.
Even a middle ground where there is no alienation, won't be any use. He won't think he has to change, some older couple won't convince him.
Listen, you know what my situation was, how miserable my day to day, you know the stuff I told X that would make me so dreadfully sad I couldn't bear to look out of the window for weeks at a time, as it would remind me where I was and then I would be enraged, or just sob. I know true despair. I could tell X in every way there was that I needed help, it needed to change, but he promised he'd consider it.... and then refused.
If I couldn't tell this man in 3 different languages why he made me so miserable I thought about walking into the sea, and he didn't flinch, what makes you think YOU could succeed? They don't CARE love.
Stop banging your head on the wall Fool, it's not going to work, it'll never work love. And certainly NEVER if you STAY with this prize twat. Where is the incentive to change?
Please, if you have not read Lundy Bancrofts book, can you kindly get it on express delivery?