I use a version* of a net-pot to flush out my sinuses after surfing. If I don't, especially if I surf in a red tide, I get a nasty sinus infection (surfers sinusitis or acute sinusitis). I even had sinus surgery to reduce my turbinates and increase my sinus ducts which helps, but still doesn't prevent the problem.

* I use NeilMed's sinus flush which basically is a sealed bottle with a straw I can use to force flush my sinuses, vs. just using gravity.

It REALLY clears out your sinuses if you have a lot of mucus (from allergies or a cold). You know how when you blow your nose, you never get everything out? Some of the mucus comes out, but some is driven up into your sinuses because the air is coming from the middle (imagine a tube full of water,and you blow into a hole in the middle... half the water will be blown in each direction)

Neti pot will get all of the mucus out (especially when i do it first thing in the morning, before blowing my nose). It comes back, of course, but having a few minutes of mucus free breathing when you have a bad cold or allergies is amazing.

My wife uses one to clear out her sinuses when they are stuffed due to a cold. Sinus infections cause her pain. Her doctor recommended it. She uses a squeezable bottle.

I made sure she only uses distilled water. She dissolves a saline powder in it.

Reduces incidents of mild sleep apnea in conjunction with nasal strips and sleeping on my side. (I determine occurrence of sleep apnea by checking if waking happens between or during sleep cycles.)

Also helps with voice work (I am a voice coach), makes for clearer mask resonance.

For me it basically cured a several-years long bout of hay-fever symptoms (constant congestion, could never get it all the mucus out) over a period of just a couple weeks of usage. I use it now just a few times of year whenever I get a cold that causes congestion, because its such a relief to get that crap out of your nasal and sinus passages.

It relieves the symptoms of sinusitis. Painful pressure can build in your sinuses, and rinsing can help open passages and equalize the pressure as well as soothe the pain a bit.

I also like to think I'm removing bad stuff and helping with the healing process, and maybe killing bad stuff by flushing it with salt water, but this is my own personal myth.

Sinus pain can be excruciating. In my mid-20s, pretty much any cold or flu I got started being followed by a sinus infection. Most of them are relatively mild, but a couple of them have been truly debilitating. Pseudoephedrine brings some relief, but has side effects. Neti pot brings additional relief, and is free of side effects. (And is much cheaper than PSE.)

I had to use one after a sinus surgery (to remove a not-so-tiny bone spur and then put things back where they belong) to flush out dried blood and whatnot.

I've used it a few times after when I have a severe head cold to open things up a bit. Easier and less invasive than going through the background check needed to buy cold medicine.