When I was 17, I had sinusitis. I went to an ear, nose, and throat doctor for treatment. The doctor prescribed for me that I mix salt and baking soda in a bowl of water. Then I was to use a plastic contraption like a squirt gun to squirt the water/salt/baking soda mixture up my nose and spit it out through my mouth. I can see how water could be squirted up the nose to loosen mucus in my nose to clear my nasal passages. What was the purpose of the salt and the baking soda in the water?