Hi Jack,
Interesting exercise. I found it quite useful but felt that the tension in my hands and arms detracted from the overall affect. It may be good to complement this with some total body relaxation, with eyes closed, as would be done in meditation.
It is valuable to consider these methods and I commend you for your suggestion.

Yes tension in hands is one problem so you should start with few minutes and later on increase the time.
Also you can rest your your elbow on your legs or table.

Combining this exercise with total body relaxation is a good idea. But here i have posted for people who don't have enough time on hand. So they can do these exercises in 10-15 minute break.

A typical dictionary definition of hypnosis states that it is: a state that resembles sleep but that is induced by suggestion. However, anyone who has tried hypnosis (and any self respecting hypnotist) will tell you that this is a very simplistic view of the subject!
A much better description comes from the Free Online Dictionary which states that hypnosis is: an artificially induced state of consciousness, characterised by heightened suggestibility and receptivity to direction. So what does this mean and how can it be used to your advantage?
Well, the subject of hypnosis has been discussed and pondered since the late 1700s. Many explanations and theories have come and gone though science, however, has yet to supply a valid and well-established definition of how it actually happens. It's fairly unlikely that the scientific community will arrive at a definitive explanation for hypnosis in the near future either, as the untapped resources of our 'mostly' uncharted mind still remain something of a mystery.
However, the general characteristics of hypnosis are well documented. It is a trance state characterized by extreme suggestibility, deep relaxation and heightened imaginative functioning. It's not really like sleep at all, because the subject is alert the whole time. It is most often compared to daydreaming, or the feeling you get when you watch a movie or read a captivating book. You are fully conscious, but you tune out most of the outside world. Your focus is concentrated intensely on the mental processes you are experiencing - if movies didn't provide such disassociation with everyday life and put a person in a very receptive state then they would not be as popular (nor would TV advertising be as effective!). Have you ever stated that a film wasn't great because you just couldn't 'get into it'???
This works very simply; while daydream or watching a movie, an imaginary world becomes almost real to you because it fully engages your emotional responses. Such mental pursuits will on most occasions cause real emotional responses such as fear, sadness or happiness (have you ever cried at a sad movie, felt excited by a future event not yet taken place or shivered at the thought of your worst fear?).
It is widely accepted that these states are all forms of self-hypnosis. If you take this view you can easily see that you go into and out of mild hypnotic states on a daily basis - when driving home from work, washing the dishes, or even listening to a boring conversation. Although these situations produce a mental state that is very receptive to suggestion the most powerful time for self-change occurs in the trance state brought on by intentional relaxation and focusing exercises. This deep hypnosis is often compared to the relaxed mental state between wakefulness and sleep.
In this mental state, people feel uninhibited and relaxed and they release all worries and doubts that normally occupy their mind. A similar experience occurs while you are daydreaming or watching the TV. You become so involved in the onscreen antics that worries and everyday cares fade away, until all you're focused on is the TV. In this state, you are also highly suggestible. That is why when a hypnotist tells you do something under trance; you'll probably embrace the idea completely. However, your sense of safety and morality remain entrenched throughout the experience and should either of these be threatened you immediately wake!
A hypnotist can not get you to do anything you don't want to do.
So while in such a state, when we are highly suggestible and open to new beliefs, a skillful hypnotist, whether in person or via a recording, can alter life-long behaviours and even give us new ones! hypnosis