The first time someone told me about Neti Pots I thought they sounded like some new age hippie yoga naturopath weirdness. And also kind of gross. Seeing a Neti Pot in person only solidified this belief. Then I tried one. And holy crap was I right!
But also, holy crap did it work.
Neti Pots have been around in the form you see here for over 40 years (and in Ayurvedic medicine for thousands.) They're a very basic nasal irrigation system that combines warm water and salt to naturally remove mucus, pollen, dust, and other crapola from your sinus passages. I mostly use one to de-snot myself when I have a cold, or feel one coming on.
As depicted in the photos, you place a full Neti Pot against one nostril, tilt your head, and let the water flow through to the other. The stream picks up and pushes out your unsavory flecks and goo along its way. If you've got the gag reflex for it (or an especially stuffed nose, in which case you may have no choice) you can tilt the water in your nose toward your throat and then hock the phlegm out through your mouth. I find this technique particularly gratifying.
The Neti Pot people also recommend their product for use on dry nasal passages, and as daily sinus "lavages" to keep the passageways clear.
The pot is made of lead-free ceramic and glaze and comes with illustrated instructions.
Note that improper use of a Neti Pot can be dangerous, and most medical professionals recommend fillings yours with filtered, treated, or boiled water. You can read more about that here.