Symptoms too minor? Bacteria grows, so it may eventually become major.
The Sinus Flush is more effective than FESS operations, because it flushes out the infected mucus from your upper sinuses, which is the cause of sinusitis
http://www.medhelp.org/user_journals/show/2322
The Flip-Turn Sinus Flush is mildly risky, because you have to bend over to do it, preferably in a shower, but you can also do it outside on soft ground, or you can kneel down and lean over a bathtub with the shower running.
The passageways to your upper sinuses are probably swollen shut, so it may take a few days for the saline to shrink the membranes and open the passages up, then you will see yellow mucus come flowing out.
Good luck