Anecdotes from my personal peanut gallery: Presumably after undergoing several adversarial attempts at amateur facial reconstruction in my earlier years, I've since endured persistent sinusoidal mysery, most notably an unreasonable susceptibility to colds. I tried many rational things which failed. However, it has been a (probably) irrational concoction that I've settled on, for 5 years now. A squeeze bottle of inert saline solution is thusly squozen and drip-fed a clean, high quality Lugol's solution (liquid iodine). At times, an essential oil is added too, eg peppermint, but rarely. At the risk of excessive iodine intake, my sinuses are now tolerable. Having doubts about this plebeian prescription, I encountered in my cursory research a patent by a prominent pharmaceutical company which consisted of the same recipe, but specifically for the "decolonization" of MRSA from the nasal passages. Considering that many folks now sport MRSA in their nasal passages, perhaps there's something to it. I've yet to settle on a suitable biofilm disruptor, but manuka honey is on my list.

If anyone is reckless enough to do the same, please thoroughly research the dangers of excessive iodine first. It is easy to err.