For smooth respiration, it is necessary that both the nostrils should be clear, with the passage inside them fully open for the movement of air. This is usually not the case with many people. It is found that one nostril works more freely than the other, sometimes the left, at other times the right. It therefore becomes necessary often to clear the nasal passage through me means. Some people habitually have one nostril partially choked. There is a kriya called Neti, which is very useful for making both the nostrils clear. A thick thread made by interlacing three or four thinner threads) softened with butter or oil, is passed through one of the nostrils, and is taken out through the mouth. The thread may be about one foot in length. Holding the two ends of the thread (one from the nostril and the other from the mouth) in the hands, the inside of the nasal passage is rubbed by pulling both the ends of the thread alternatively to and fro. When one nostril is cleaned, the thread is taken out from the mouth. After washing the thread with clean water, it may be inserted through the other nostril, and the whole procedure may be repeated. This is described in the Hathayoga – Pradipika . Instead of a thread of cotton fibre, a rubber catheter of suitable thickness may be used with advantage. A mild form of Neti can be performed with lukewarm water to which a pinch of table salt is added. A feeding cup with a long spout is required for this purpose. The cup is filled with water, and stooping a little forward and tilting the head on one side, the spout is inserted slightly inside the upper nostril, and water is poured into it. Water should not be allowed to go down the throat. It comes out through the other (lower) nostril. The procedure may be repeated by tilting the head on the other side, and pouring water through the other nostril which now comes up.
Drinking water through the nose may be called a modified form of Neti. Water (which should not be too cold or hot) is taken in a bowl, and both the nostrils are partly dipped in it. Now tilting the bowl a little, the water is allowed to go down the nostrils, by Sucking very gently. This causes irritation of the inside of the nasal passage, in the beginning, because water comes in contact with the upper side of the nasal passage, which is very delicate. In course of time one learns how to allow the water to pass only through the lower part of the nasal passage, and then there is no irritation. Drinking water through the nose is a very useful practice, especially in warm climate, because it cleans the ;nasal passage, and has a soothing and refreshing effect not only on the nasal canal, but on the brain and the eyes as well. Traditionally. water is kept in a clean copper vessel at night and is drunk through the nose early in the morning. An experienced person can easily empty a full glass of water through the nose within one or two minutes. It is, of course necessary to clean the,nose in the usual manner before drinking water through it. Yogic breathing can be enjoyed better when both the nostrils are thus made clear. Persons having a deviated nasal septum or any other disorder of the nose, would however do well to obtain medical advice before taking to the practice of yogic breathing.