There is an old Tibetan technique called "The Lions Roar." If you are angry, sexual, filled with hatred, jealousy, then the Tibetan master will give you this technique, "The Lions Roar." You have to sit before a mirror and you are to imagine that you are a lion, not a man. You have to make your face like a lion, you have to put your tongue out, and you have roar. And you have to practice it so that the imagination becomes so true that you forget that you are a man daydreaming that he is a lion. And when the point comes when you have really fallen prey to your own imagination, and you have become the lion, and a real roar comes out of you, suddenly you are transformed. In that roar, all hatred, anger, sex, disappears, and you will fall into a deep silence such as you have not known before. In old Tibetan monastery's they have a special room with many mirrors. Whenever someone is suffering from something like anger, hatred, or jealousy, he is to be sent to that mirrored room and he has to remain their until he comes to a climax. And when he comes to the climax, the whole monastery will know, because a real lion will be roaring there. To us, he has gone mad. The whole monastery will gather and welcomed the man, and he will come out a totally different man, It may take three days, it may take seven days. Food will be supplied to him, but he is not allowed to come out. He has to persist in imagining that he is a lion, until from the very roots of the unconscious the roar comes. The whole body is involved, every cell of it; every cell in it roars, and in that roar everything is thrown out. It is the deepest catharsis possible. And you will never see that man angry again because now the poison is not there. For the first time the face will become human.
OSHO
Vigyan Bhairav Tantra. Volume 2.