Healthwise

Flushing the nose and sinuses with saline—a salt water solution—can be part of a treatment for sinus infections, colds, and allergies. This method works by rinsing mucus and debris out of the nasal cavity. Neti Pots are one option, along with over-the-counter saline sprays, as well as an irrigator bottle with salt water you make at home.

Whether this treatment is safe or not comes down to hygiene. There have been cases on the mainland where people acquired potentially deadly amoeba infections because the water they used to flush their sinuses wasn't sterile. Be sure to clean and dry the Neti Pot after each use and use distilled water or water that's been boiled or filtered to mix the saline solution.