Working with a gymnast new to Shaposh recently, I was wishing we had a Quick Flex Bar. This is by far the best way for kids to get started on all counter rotating releases.
Click PLAY or watch it on YouTube.
The hands are the only point of force application. Of course that hip action is needed to put more weight on the rail. The equal, opposite and simultaneous reaction force is what generates the counter rotation.
Gymnastics Coaching.com 