You are getting great advice here. The trick is to see what you think will work for your situation, try it, and then if it works great but if it doesn't try changing things again.
I found the confrontational approach worked with my H but it is very hit and miss. I didn't know about DBing when that happened and am not sure what I would have done, if I am totally honest, if I had known then what I know now. So much of the confrontational approach strikes me as down to luck. I was lucky that the A my H was having was coming to a natural end - it wasn't at it's headiest heights when I was told about it. I firmly believe my H told me about the A because he wanted me to help bring it to an end and see off the OW - but it was all such a mess and hindsight is a wonderful thing. Having said that I am now coming up to 18 months post bomb and my M seems to be doing pretty good.
One thing that I have found useful from here, (although I am not always great at doing this), is the 48hr rule. Whenever you want to react strongly to something your spouse has said / done - if you can, wait 48 hrs to respond, so that you don't lash out in anger and you really do mean what you say / do.
And remember, like with children, don't threaten ultimatums unless you are willing to follow through.
Good luck
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength
