For the first 1,000 days, the monks ceased all food except nuts, seeds, fruits and berries and they engaged in extensive physical activity to strip themselves of all body fat. For the next one thousand days, their diet was restricted to just bark and roots. Near the end of this period, they would drink poisonous tea made from the sap of the Urushi tree, which caused vomiting and a rapid loss of body fluids. It also acted as a preservative and killed off maggots and bacteria that would cause the body to decay after death.

In the final stage, after more than six years of torturous preparation, the monk would lock himself in a stone tomb barely larger than his body, where he would go into a state of meditation. He was seated in the lotus position, a position he would not move from until he died. A small air tube provided oxygen to the tomb. Each day, the monk rang a bell to let the outside world know he was still alive. When the bell stopped ringing, the tube was removed and the tomb sealed for the final thousand day period of the ritual.

At the end of this period, the tomb would be opened to see if the monk was successful in mummifying himself. If the body was found in a preserved state, the monk was raised to the status of Buddha, his body was removed from the tomb and he was placed in a temple where he was worshiped and revered. If the body had decomposed, the monk was resealed in his tomb and respected for his endurance, but not worshiped