Neti pots are a great way to both clean your sinuses and gross out your friends.

Neti pot users pour water into their noses using the pot's spout, letting the liquid clear any dirt and mucus out of their nose before falling out the other nostril.

It turns out, however, that when using a neti pot, it's incredibly important to use sterile or saline water, or you could be at risk of something far more dangerous than a nose full of water.

A 69-year-old woman from Seattle who regularly used a neti pot died earlier this year after doctors discovered her brain was being eaten by amoebas. The physicians believe filtered tap water was the source of the amoebas, which entered her cranial passage through her nose when she used the pot.

Charles Cobbs, one of the operating neurosurgeons at Seattle's Swedish Medical Center, told The Seattle Times:

"When I operated on this lady, a section of her brain about the size of a golf ball was bloody mush. There were these amoeba all over the place just eating brain cells."

The Centers for Disease Control and Prevention say that there are several varieties of amoeba often present in fresh water that can cause brain infections. One such amoeba, Naegleria fowleri, is responsible for most brain infections, though such instances are very rare.

The CDC states:

"There have been 34 reported infections in the U.S. in the 10 years from 2008 to 2017, despite millions of recreational water exposures each year. By comparison, in the 10 years from 2001 to 2010, there were more than 34,000 drowning deaths in the U.S."

Don't worry—these infections can't be spread through a chlorinated pool, or even by drinking contaminated water.

Where should you watch out for the nasty amoebas?

According to Fast Company, "warmer waters in the south," though some scientists believe climate change may soon change that to "warmer waters everywhere."

Twitter users were scared for their brains.

Maybe think twice before you use a neti pot. And if you're going to, be sure to use sterile water!

H/T - Fast Company, NBC 12