See http://www.sinusitisfaq.org/

Longer term, you are going to have to eliminate whatever is causing your
sinusitis - quite possibly dust or mold if your symptoms are worse in the
winter.

I'm not a medical expert so I can't say if nasal rinse will work in
your case.
I had a problem with post-nasal drip for years. The thickening of
mucous left an unpleasant taste in my mouth. Daily nasal rinse works
brilliantly for me. You'd be amazed at how much crap gets stuck in the
nasal cavities. Earlier I was using the neti pot system which was fine
but cumbersome to use.
Now I use the kit by nasopure. Just pour water and saline solution in
the ergonomically-designed bottle, close cap and shake. It's very easy
to use.

www.nasopure.com

I had a few questions and found Dr. Hana Solomon at nasopure to be
very helpful.

You can also buy the saline packets from neilmed.com (it's cheaper).
But the bottle from nasopure is the best.
Email me if you have any questions.

Hope that helps.