The two-handed wrist grab is always a dangerous technique to teach little kids, they always seem to hit themselves in the face some how. No matter how many times I show them the proper way to do the technique, someone is going to mash their own nose, or poke themself in the eye. It’s inevitable.
The two-handed wrist grab defense is used when someone grabs your wrist with two hands, you make a fist and with your opposite hand pull the other free. It’s Bully-Basics 101. Kids dig it, adults raise an eyebrow, but the physics of it are legit and once we understand how it works, it only helps us understand the mechanics of other techniques.