My only constructive thing to add to this thread is that the point of DB is not to end affairs, it's to save marriages. Those are sometimes VERY different goals.
Ending an affair does not necessarily ensure a saved marriage, ESPECIALLY if the LBS doesn't ever really take stock of their OWN contributions to the bad marriage.
The affair is only ONE problem in any marriage. A big one, but in almost, aw hell, call it EVERY case there is much more wrong than cheating and by only focusing on the affair, not only is that WAS in denial of that fact, but the LBS becomes that way too.