Unfortunately, there isn't a straight yes or no answer to this question as it depends on the level of the alcoholism and the person having the treatment has to want to change their behaviour and dependency on alcohol.
Hypnosis has been used in the treatment of addictions for many years and has proven to be a good tool to use to combat cravings. It uses the power of suggestion and helps the addict to change their behaviour patterns. It isn't a standard form of treatment but can be successful as long as you have an open mind when accepting the therapy.
What you must bear in mind is that it won't take just one session to make everything go away, you will need several sessions before feeling the full benefit. The hypnotherapist will first of all ask you all about your complete history before starting any therapy treatment, they will need to find out why it is that you've become an alcoholic so that they can better understand and give the correct therapy.
In order for the hypnotherapy to work you have to be responsive to the hypnosis treatment and don't worry because contrary to popular belief a hypnotherapist cannot make you do something that you do not want to do, so you won't be squawking like a chicken if you think of having a drink. They will use other powers of suggestion such as every time you see a green car you will say to yourself that you do not want a drink and that you will not drink. Hypnotism for alcohol rehab can work as long as you are open and willing to give it a go.
Find out more about how to stop drinking.