Loading ...First , sinus flushing – I have done that for over four decades due to pollen allergies , using a Hindu Neti pot , a gravity feed , heated saline rinse into one nostril out the other . You can feel it penetrate into swollen sinus channels and flush them out . As you point out , during the pollen season it can help immensely .
Goldie – the barotrauma concept sounds plausible . Every foot of depth adds about a half PSI , so at 20 feet down , the pressure is getting close to two atmospheres , which could drive water far back into the sinuses .
Thanks to both of you for your responses .