Nearly everyone who tries to implement this technology for creatively resolving interpersonal conflict finds themselves from time to time feeling frustrated. Your frustration can be a great teacher. It will instruct you about unconscious choices you are making that thwart your efforts. Pay attention to your own distress!
A good place to start with this is to ask how you know that it isn’t working. What is the evaluative instrument you are using to determine whether this new approach is working?
Almost always the problem is some version of either not paying attention to how you are changing or focusing too much on whether the other is changing.