He hasn't been brainwashing her for years, that's absurd. It's not like he was raised as a JW or ever really and truly lived as one. He was at a weak point, was spiritually curious, was love-bombed by the JWs and then intimidated in a whirlwind. He's still at a point where he could go either way. No person is worth giving up on without even trying, especially since you love him and I'm sure he really does too. It's worth a try.
Especially regarding false prophecy, disfellowshipping, child abuse, etc.