First, and forgive me if I am preaching to the choir, but are they fixed? If not, I would keep them completely separated until they are fixed and have been for a few weeks to let the hormones die down. Doing this will ease the process tremendously because their hormonal instincts will no longer be driving their buses.
If they are already fixed, then I would say that Millie actually wants to be dominant. By her asking him for affection, she is telling him he should take care of her, that he must answer to her demands. She is happy to leave him alone until he tries to upset what she assumes is the hierarchy (her alpha, him subordinate), which is why she is whipping around to growl and box at him. So they have some stuff to figure out.
I do like your stunt double idea, that can be very helpful. Try leaving it with him all the time so that he is in as much contact as possible with it and can get used to being closer to her scent.
You might try doing some car rides too when starting bonding sessions. Get a friend to drive around while you sit in the back seat with them. If they try to climb into your lap, pick them up and put them back together again. You want them to focus on each other, not you, for support. Do this for 20-30 minutes, then when you get home put them in a neutral space (I like using the dining table top with a towel on it for traction) and supervise them while they hang out there for about 15 minutes. If they start to look agitated, stop the session and put them back in their pens. Stopping fights before they can start helps the bonding process tremendously. If they make it 15 minutes with no problems, still stop it, you also don’t want to push the bonding session into a fight session by accident from too much time together.
If car rides are not an option, try putting them together in a neutral area and run a vacuum near by. The noise will stress them a little and make them want to take comfort in each other’s support rather than fighting.
For more ideas try these pages
https://binkybunny.com/BUNNYINFO/tabid/53/CategoryID/9/PID/940/Default.aspx
http://www.thebunnyguru.com/care-guide/bunny-bonding/
Good luck!