Purification is of two kinds: Antar-Dhauti (internal cleaning) and Bahir-Dhauti (external cleaning). Antar-Dhauti can be made in three ways. Take a fine piece of muslin cloth, 3 inches wide and 15 feet long. The borders should be stitched well and no pieces of loose thread should be hanging from its sides. Wash it with soap before use and make it clean. Dip it in tepid water. Squeeze out the water and swallow one end of it little by little. On the first day swallow only one foot. Keep it there for a few seconds and then take it out very slowly. On the next day swallow a little more and keep it for a few minutes and then take it out slowly. Thus little by little you can swallow the whole length, retain it for about 5 minutes and then take it out. Do not be hasty. Do not injure your throat by rough handling. When the Kriya is over drink a cup of milk. This is a sort of lubrication for the throat. This exercise should be done when your stomach is empty. Morning time is good.
You need not practise this every day. Once in 4 days or a week is sufficient. This exercise cannot at all do any harm if gradually practised. Everyone will feel a little vomiting sensation on the first 2 or 3 attempts. As soon as the Kriya is over, wash the cloth with soap and keep it always clean. This is an excellent exercise for those who are of a flabby and phlegmatic constitution. Gradual steady practice cures Gulma, gastritis, dyspepsia, diseases of the stomach and spleen, disorder of phlegm and bile. This exercise is also known as Vastra Dhauti. This is one variety of Antar-Dhauti.
There are some people who can drink plenty of water and pass it through the anus immediately. It is called Varisara Dhauti. This is an effective method. This exercise is also known as ‘Sang Pachar Kriya’. Yogi Sambhunathaji of Kishkindha is an expert in this Kriya. This is not possible for the vast majority of persons. Nauli and Uddiyana Bandha should be combined for performing this exercise. Even the smoke of a cigarette can be passed out through the anus.
Drink a large quantity of water and shake the abdominal portions. Contract the stomach and vomit the water. This exercise goes with the name ‘Kunjara Kriya’. This is also a kind of purificatory exercise.
Internal cleaning can be made also by swallowing air. Fill up the stomach with plenty of air. It is done by hiccough. Just as you swallow food little by little, so also you can swallow air and fill up the stomach and intestines. You will have to learn this from the man who can do this Kriya. When you contract the abdominal muscles, the air will pass away through the anus as Apana Vayu. Those who can fill up their stomach with air, can float on water just like a dead body and can also live on air and water alone for some days without any food. Those who can do Antar-Dhauti in any way, need not go in for any purgative or laxative. They will never suffer from indigestion or constipation.
There are some other Dhautis, viz., Danta Dhauti (cleaning the teeth), Jihva Dhauti (cleaning the tongue), Karna Dhauti (cleaning the ears), Mula Sodhana Dhauti (cleaning the anus), etc. These are being done by you all everyday. I need not tell you much about these.