I can't recommend enough the sinus rinse. I do it every morning in the shower, it's just easier that way.
At my worst, I had five sinus infections in just a little over a year. I had allergy testing, nothing significant resulted. But since I started the rinses, I've only had about two sinus infections in the past 15 years!
I use plain tap water with a little baking soda -- seems to go better than salt. I got the squirt bottle from the allergy doctor, so maybe check with your ENT...