Just to be perfectly clear I have no idea what actually goes on within other Isshinryu programs. I am just a product of the training I received in Tom Lewis’ dojo in Salisbury and with Charles Murray.
Sure I know at least everyone studies some version of Chart 1 and Chart 2. And all use similar versions of the same kata. But the actuality of what training in followed in detail, I really have not seen anyone talk about that.
Very early after I started I was shown a 2 handed wrist grab release. Practiced it, got good at it and kept it ever since. Perhaps everyone does it, I have no idea. But I would hate to have it lost, it is that good.
So start with the attacker grabs both your wrists to control you.
Of course there are many possible answers. This is what I was taught.
1. Splay open the fingers of both your hands (this causes the attacker to adjust their grip to a small degree.)
2.When the fingers are splayed open, press outward with your wrists. Opening the grabbed arms wider. (The attacker will respond by pressing inward harder to keep control.)
3. Then suddenly slam your arms together. (The attacker pressing inward is a force enhancer that you are using his motion against his control.
4.a. If you want to move right. Slam your right arm into you left splayed fingers, grabbing their left wrist.
4.b. If you want to move left, Slam your left arm into your right splayed fingers, grabbint their right wrist.
5. In either case you are now controlling both their hands. One of them is grabbing a wrist and that hand in turn is grabbing the wrist of the other hand.
6.a. As you establish control of both their hands, your right foot steps out to the right, slightly forward. At the same time you snap your right arm back into standard chamber.
6.b. As you establish control of both their hands, your left foot steps out to the left, slightly forward. At the same time you snap your left arm back into standard chamber.
7. As your free hand is in chamber, immediately strike with the free hand, such as to the face, jaw, neck or ribs. In practice we normally struck to the face. (you have the choice of target of opportunity in any case).
This is very swift and your hands move quicker than their ability to adjust their holding grip.
To be perfectly clear there are innumerable excellent double wrist grab releases. This one has always served me well.