I have used silver spray for sinus infections and eye infections, and found when I used it at onset, it cleared it up quickly. I am eager to hear more if there are any health concerns. I only use it for a limited time and only in avoidance of antibiotics.

For prevention of sinus infection I prefer a warm saline wash (netti pot or nasopure). When my children were very young I found a spray containing Xylitol (sugar from birch trees) was a great preventative, and easier to administer than the saline (quicker on a squirmy baby :)