A neti pot is for nasal irrigation. Filled with a solution of pure water and salt, neti pots help you clear out any allergens or excess mucus that are clogging up or irritating your nose. You’ll have less congestion and  breathe easier through your nose. Many doctors recommend using a neti pot for general nasal congestion as well as colds, allergies and sinus infections.
 
Microscopic, hair-like structures called cilia line your nasal cavity and the surrounding sinuses. Cilia help to usher mucus out of your nose. Nasal irrigation with a saline solution helps the cilia work better at getting rid of mucus and unwanted particles (like dust, pollen, etc.) that often lead to sinus issues.