To cleanse the nasal passages with saline, it is important to avoid the cold period and when the nasal passages are not well ventilated and have more pus nasal discharge, and try to ensure that it is done in a state of nasal ventilation. There are two ways to apply it, such as nasal aspiration by yourself, you can scoop up the saline with your hand, while the nasal cavity is immersed in water, and rinse the nasal tract by suction aspiration of saline, the strength of this must be mastered, be careful of choking the saline into the trachea and cause danger. If you think this method is not very reliable, you can buy a nasal washer, which can clean the nasal cavity by squeezing the saline into the nasal cavity through the pressure of the balloon.