I know the feeling all to well. The one thing that stops me from doing it, is knowing that just like nothing I can say or do makes a difference to my H, it wont make a difference to the OW either. They are in just as much of a fog as our H's are. It is just your way of trying to gain some sort of control over the sitch and I know all to well that struggle. That is my daily struggle. Just know, that nothing will come of it, and if it does not go the way you want, it will just add more hurt and disappointment, so better not to even worry about it.
Ultimately regardless of the OW, it is our H's who made the decision to be with the OW. No one can make us do anything, we make our own decisions, and even though my own H will not own up to that and wants to blame me, I am starting to figure that out. Just like I can not make him come home, the OW did not make him choose her, he ultimately did it, and he is a grown man and now has to live with his choice.
Just don't do it, no good will come of it, and it will not help you feel better, even though you think it will.