Actions or processes we do on a regular or in fact irregular basis, will follow a pattern, a sequence, which will be automatically followed, without us on a consciously being aware of what is happening.
Take shaking someones hand. As a person walks up to another, they will often offer up their hand to shake the other persons hand, and that person will automatically raise their hand to grasp and shake the hand. It is automatic.
If one of the people fails to return the handshake grasp, the one receiving the hand will fell very uneasy, they will not know what to do. If at this time, that person is offered an easy achievable task or action, that is not against their beliefs, culture of religion, they will most likely follow that suggestion.
In the video, we can see participants in trance after being offered by Phillip Holt to shake their hands. This offer was withdrawn just before the grasping of the hands, and the participants hand raised into the air and suggestions made that it will hang there as they go into a deep trance.