 As described in a 2011 review in American Family Physician, nasal irrigation with salt water, using something like a neti-pod, has been shown to be beneficial for those suffering from sinus infections, a safe and inexpensive treatment option for patients seeking symptom relief, an opinion shared by none other than the Cochrane Collaboration, probably the most prestigious source of evidence-based medical research analysis. So what's the downside? Well, as with any alternative or complementary medicine modality, there's always a concern that it could potentially delay treatment of serious disease, but for non-severe symptoms in immuno-competent individuals, just mild pain and fever, symptoms lasting less than a week, nasal irrigation can work wonders. But the reason I bring it up is that an abstract presented at a medical conference in 2009 suggested chronic nasal irrigation may result in more frequent, recurrent attacks of sinusitis, and a new study appears to have figured out why. People were reinfecting themselves with contaminated neti-pods, called here irrigation bottles. They cultured bacteria out of 97% of the bottles collected from people who used them for recurring sinusitis. Under a microscope, they demonstrated biofilm formation, bacteria stuck to the inner surface so you can't just rinse them out. The same bugs that caused your sinus infection in the first place may just be sitting there waiting to reinfect you later on. The good news is that they found simple cleaning methods. Washing them out with boiling water or microwaving them for two minutes did a good job of sterilizing them so they are ready and clean for their next use.