On August last year 08/2008, I comment on how I used H2O2 to treat my synus problem. I would like to add a WARNING: applying the nostril spray continuously came eventually (after many weeks) to be very irritant and my mocus fluids increased, yet still clear. So I have discontinued the nasal spray that way. At least the spray got rid of my sinus infection at the beggining of the treatment, I am sure. Therefore I will recommend the nasal spray as I did only to clean yr sinus, one time, using the spray mix for only 2 to 4 weeks and stop. Now, I am taking several drops of Food Grade peroxide in fresh coconut water (abt 8 oz in a nut) daily instead, as a preventive way to help my inmune system against any potential illness. You never know!