Shatkarma also known as Shatkriyas, are a set of Hatha yoga purifications of the body, to prepare for the main work of yoga towards moksha (liberation). These practices, outlined by Svatmarama in the Haṭha Yoga Pradīpikā as kriya, are Netī, Dhautī, Naulī, Basti, Kapālabhātī, and Trāṭaka.
The six purifications taught in the Hatha Yoga Pradipika, and repeated in the Gheranda Samhita, are:
1- Netī , a nasal wash. This is the practice of using a neti pot to cleanse the nasal passages. A basic neti wash consists of purified water and non-iodized salt, to create a gentle saline solution.
2- Dhautī , the cleansing of the whole digestive tract.
3- Naulī , a self-administered abdominal massage, using only the muscles of the abdominal wall. The practitioner stands with the feet about hip width apart, hands on knees, and body at about a 45 degree angle. The core is rotated internally by moving the abdominal muscles alternately in a clock-wise, then in a counterclock-wise direction.
4- Basti , a colonic irrigation.
5- Kapālabhātī , a skull polishing, and is a pranayama (breathing) practice intended to energize and balance the nadis, and the chakras. Specifically, it is a sharp, short outbreath, followed by a relaxation of the core that allows the body to inhale on its own.
6. Trāṭaka , gazing at a fixed point such as a black spot or a candle flame