It wasn't until I was considering yoga teacher training in India that even learned about the existence of many of these practices. 

Jal Neti - Sinus Irrigation

I knew already about the neti pot and had already been using a modern version in a squeeze bottle for years, at the recommendation of my ENT. He told me that I could use this neti pot up to three times per day if needed.

So I was already familiar with the benefits of cleaning the sinuses with water. Such as lessening allergies, viruses and bacteria in the nasopharynx. This is a place in the respiratory tract where many respiratory viruses first take hold upon exposure.  The sinuses act as a filter and this is an important part of our immune system. There are many hairs or cilia that naturally trap particles, bacteria, viruses, allergens and other things. These hairs with assistance of immune cells and mucous remove and drain them away. At night when you're sleeping you may experience the post nasal drip of these particles deeper into the respiratory tract down the back of the throat. Which is why we want to clean our sinuses regularly. We shower, brush our teeth and perform many other hygenice processes everyday. This is part of yogic hygiene.

Many studies suggest regular irrigation can prevent and lessen the severity and duration of respiratory illnesses.