I have heard that advice from friends when I initially realized I may very well lose my W. The initial reaction from W was: "hahahaha NOW you want to work on it". and "Nothing will make me want to stay". This was I think BEFORE or right at the moment she was speaking to OM.
My W's reaction changed when I stopped asking that question and started showing changed behavior. When I stopped asking her if she noticed my changes and making promises that I need one more chance yada yada
Certainly, if you have NOT had that conversation or don't know what it is she is missing you can try to squeeze some of that information out.