First a little background. When you go to a doc and get some antibiotics what happens. Well you kill the bacteria causing the infection of your sinuses. This assumes the antibiotic works. Yes, but what else happens. You promote yeast fungi infections.
The mechanism is that you kill off the bacteria, but that bacteria competes with yeast, fungi and encourages their growth. Females end up with a yeast infection that is obvious to them and males do to, but not as obvious to them because of sexual differences. Do fungi and yeast grow rampantly in your sinuses. You bet cha....
The treatment. Cheap and effective. Iodine. Use a netti pot, but instead of just salt water in it add one drop of iodine. You know the stuff....tincture of iodine. Same stuff that was used years ago and kills all bacteria, yeast and fungi. Three bucks in the local pharmacy.
I would do it three times a day, but the most important time is bed time. That sinus infection can and will sometimes drain into your lungs at night and cause bronchitis and all sorts of mischief. I would do it for a week and consider doing it periodically to keep those evil spirits away ( bacteria, fungi and yeast).
I had sinus problems brewing for at least eight years with a sore in my nose. Everyday I was blowing blood and green stuff out of my nose. Some days worse than others. The sore is gone and so is the sinus infection.