I have done it 3x in the past 10 years. You have to have the right ingredients. It isn't easy but really cleans you out. there are many products out that do similar things with good results. I would suggest pulling it up on the web and read about it before trying it. The first 3 days are the worst. After that, it is pretty easy. The longest i was able to stay on it was 10 days. You must gradually add food back in...follow the instructions carefully.
Good luck! I am thinking of doing it again after Christmas!