I know the wall well! But unfortunately, I don't think there is a way for you to tear it down if she is intent on building it. The DB book does say that if the WAS has already checked out of the R, no amount of effort can turn her around. So she is the one that needs to take it down, not you.
How did I deal with it? Poorly. I beat my head against that wall time and again. But it wasn't until I was prepared to move on without her that I started to pull my life together again. So when she had second thoughts and looked back towards our M, she saw something she wanted to come back to and realized what she was losing. Had I not made those changes, she would have looked back, saw more of the same, and kept going.
So my changes didn't make her change her mind. But they created a win-win situation for me. My life was moving in a positive direction with or without her. Of course in the end I did get my M back. But even though DBing promotes itself as a marriage-saving strategy, I think it is more of a life-saving one. It is for YOU that you do these things. I have read others say that the best DBing happens after you give up. I think that is true.
Me45 W35 M6 T8 D16 SD11 D0 Dec 07: Bomb July 08: Busted! Thread