Next time you use a sinus flush, you might want to be careful of what you put up there. Two people from Louisiana have died recently from a brain-eating amoeba that's been linked to using neti pots, the small watering can that's been recommended to relieve nasal congestion. The state's Department of Health and Hospitals has issued a warning against improper use, but said some simple steps can prevent the fatal infection. Use only distilled, sterile or previously boiled water, but definitely not tap water. The amoeba, Naegleria fowleri, enters the body through the nose and causes a brain infection that's similar to meningitis. If untreated, it can cause death in 1 to 12 days, which is what happened to a 51-year-old woman and a 20-year-old man recently. Experts still highly recommend the treatment—just don't misuse it.