Mel,
 I'll repost the "evidence" from the cochrane review:
Dear Clinician,

Here is the information you requested (sourced from Reuters Health).

Nasal saline irrigations relieve chronic rhinosinusitis

By Will Boggs, MD

Nasal saline irrigation improves symptoms in patients with chronic
rhinosinusitis, according to a report in the July 18th issue of the
Cochrane Database of Systematic Reviews.

"Saline irrigations are not just a 'feel good' treatment," Dr. Richard
Harvey, currently at the Medical University of South Carolina,
Charleston, told Reuters Health. "In chronic sino-nasal disease, the
use of topical nasal saline, while not more effective than
prescription medications, improves clinical outcomes and can be
included in the treatment plan."

Dr. Harvey and associates assessed the published evidence for the
clinical effectiveness of topical saline therapy in the management of
the symptoms of chronic rhinosinusitis.

Saline irrigation was better than no treatment for improving symptoms
and disease-specific quality-of-life scores in three studies that
investigated this treatment, the authors report, and saline improved
disease-specific quality-of-life as an addition to oral antihistamine
therapy in one study.

In contrast, saline did not improve disease-specific quality-of-life
scores over a reflexology control or over intra-nasal steroid in two
studies.

In the two studies that compared isotonic with hypertonic saline,
there was no difference in benefit between the two concentrations.

"We currently have several studies focused on the efficacy of
different delivery techniques (there are numerous varieties on the
market - pump sprays, pressurized sprays, squeeze bottles, Neti pots
and nebulizers)," Dr. Harvey said.

"Some of the most frequently asked questions involve the optimal
delivery technique, volume, and frequency for using nasal saline," he
added. "While this is an area of ongoing research, my clinical
judgment and experience from working with world leaders in nose and
sinus care suggests that squeeze bottles ... and pressurized sprays
which can deliver high volumes under positive pressure are probably
the most effective."

Cochrane Database Syst Rev 2007;3. [<http://imageb.epocrates.com/
mailbot/links?EdID=34565843&LinkID=11935>Cochrane review]

However, personal experience trumps meta-analysis.IMO
Judy

Frank and Judy:

Yes, I read tje study you posted. All I'm saying is that irrigation does not
seem to help ME.

That being said, I just tried the Netti-pot last night. It didn't help
symptoms and afterwards I got a huge bad headache (but it might have been
brewing before I used it).

I'm going to try again when I get home from work late this afternoon.

Frank -- To my pleasant surprise I am finding it easy to use and not that
messy when done over a sink.

Judy and Frank: I've never gotten much GUNK out that I can see. The liquid
flows smoothly going in one nostril and out the other. My symptoms generally
do not include any kind of stuffed nose/blockages. Buy my sinuses feel
inflamed, my throat gets very sore, I feel very crappy/sick (kind of like
having a fever but my temp stays at about 98.9)

I assume all this is due infective material due to post nasal drip? Does
that make sense?

Mel