Definition - What does Samanu mean?
Samanu is an advanced method of purifying the body's energy channels known as the nadis. This practice combines several yogic techniques, including pranayama, japa (a meditative chanting of mantras) and chakra visualization.
It is believed that the prana, or life-force energy, travels through the nadis, so if the nadis are blocked, the prana cannot flow freely. Samanu is one of two methods of purifying the nadis and is achieved through the mind. Nirmanu is the other method, and it is a physical cleansing.
Yogapedia explains Samanu
Samanu is often practiced using the bija (seed) mantras of the elements: yam (air), ram (fire), tam (water) and lam (earth). Typically, the practice of samanu would follow a procedure similar to this one:
The yogi sits in a comfortable position like padmasana (lotus pose) and begins alternate nostril breathing, repeating the bija mantra yam. After finishing a cycle, the yogi switches to the next mantra and complete another cycle of alternate nostril breathing, working his way through the mantras. The yogi may also focus on a related chakra. For example, while reciting yam, the yogi focuses on the anahata (heart) chakra.
Samanu is not self-taught and should only be practiced under the guidance of a yoga instructor.