Vomiting as a cleansing procedure is used not only by people but even animals – cats and dogs especially eat grass to cause this reflex. Vomiting is a natural reaction of the body provided by nature itself. Yogis use this technique consciously to strengthen their bodies. This procedure is much more effective than any drugs and does not cause side effects
After eating in about an hour when the food has already left the stomach drink slightly salted water until the stomach is full. Then you need to bend over to induce vomiting irritating the root of the tongue with your fingers and slightly pressing on the stomach with your other hand. Continue the process until all drunk water has come out. For greater purification the entire procedure is repeated several times, resting after each round.
The described above can be performed while standing on the head (Sirsasana) so that the water stays in the stomach longer without penetrating the intestines. But only very trained yogis can do this.