Actually I used a variation of this technique years ago when my kids were little.
It worked for me. Admittedly, some people thought I was nuts but what the heck....
It usually worked.
But did you give in and provide the cookie or did you just get the kid to better express his desire and then still deny it?
Watched the video from this guy, tried out the techniques. They work.
It’s also funny, now, that the cave(wo)man has turned three and has some sense of shame as well as budding logic skills,
to demand that she throw a “better” tantrum.
“Oh, come on, you can do better than that! Kick your feet more! Pound the floor with your hands!”
She gets embarrassed and stops, most of the time.