This was my problem, but I have a solution!
With Brent stole, you allow the slack to move behind the horizontal string and around the yoyo.
Instead, intercept this slack BEFORE it wraps around the back string with your index finger, the same index finger that is holding the back strong. Let this loop fall into the gap of the yoyo, and you should have a hook.
In Brent stole, the motion with your nth is practically nonexistent; but in hook you need to intercept the piece of slack bodies it reaches the back string and let it fall over into the gap of the yoyo.
Hope this helps!