The first, or cleansing, is effected by the six processes known as the shatkarmma. Of these, the first is Dhauti, or washing, which is fourfold, or inward washing (antar-dhauti), cleansing of the teeth, etc. (dantadhauti) of the “heart” (hriddhauti), and of the rectum (muladhauti). Antardhauti is also fourfold – namely, vatasara, by which air is drawn into the belly and then expelled; varisara, by which the body is filled with water, which is then evacuated by the anus; vahnisara, in which the nabhi-granthi is made to touch the spinal column (meru); and vahishkrita, in which the belly is by kakinimudra filled with air, which is retained half a yama, and then sent downward. Dantadhauti is fourfold, consisting in the cleansing of the root of the teeth and tongue, the ears, and the “hollow of the forehead” (kapalarandhra). By hriddhauti phlegm and bile are removed. This is done by a stick (dandadhauti) or cloth (vasodhauti) pushed into the throat, or swallowed, or by vomiting (vamanadhauti). Mudadhauti is done to cleanse the exit of the apanavayu either with the middle finger and water or the stalk of a turmeric plant.
Vasti, the second of the shatkarmma, is twofold, and is either of the dry (shuska) or watery (jala) kind. In the second form the yogi sits in the utkatasana posture in water up to the navel, and the anus is contracted and expanded by ashvini mudra; or the same is done in the pashchimottanasana, and the abdomen below the navel is gently moved. In neti the nostrils are cleansed with a piece of string. Lauliki is the whirling of the belly from side to side. In trataka the yogi, without winking, gazes at some minute object until the tears start from his eyes. By this the “celestial vision” (divya drishti) so often referred to in the Tantrika upasana is acquired. Kapalabhati is a process for the removal of phlegm, and is threefold – vatakrama by inhalation and exhalation; vyutkrama by water
drawn through the nostrils and ejected through the mouth; and shitkrama the reverse process.
These are the various processes by which the body is cleansed and made pure for the yoga practice to follow.