In my case, relocation.
I just couldn't abide the air quality where I used to live.  So I sold
my home and moved elsewhere.

After surgery, relocation has been the most effective thing for me.
Polyps have not returned as often and symptoms have been much milder.

Check the air quality where you live.  I'm referring to pollution as
well as allergens.  The website www.scorecard.org shows you the
pollution data for your Zip code, right from the EPA's own monitoring
stations.  If it's real bad, you should consider moving elsewhere.

I have had two surgeries over the last 3 years for polyps.  I ran into a
person that had been using Pulmicort Respules with saline to rinse his
sinuses and his doctor found that the polyps went away.  I went to my doctor
with this and he gave me a prescription.  My ENT said that I had little
signs of the polyps after using this for about 6 months.  Much better news
that I would have gotten without this new treatment.  At first I used this
once a day for a week or two along with the Itraconazol that I use, perhaps
one in the morning and the other in the afternoon.  After things settled
down I just use the Pulmicort about twice a week and that seems to keep the
polyps from coming back.

http://gyxe.com/sinusitis/132-602-tx-for-nasal-polyps-read.shtml

Here is a link to the original discussion that I found.  I use a rubber bulb
like for this but if you pretty much follow "Dave's" notes it should work.
If I had not found this I am sure I would be headed back for another
surgery.  My allergist says he has asked around about this and it is
becoming a known treatment.  I wish you the best of luck with this, there is
nothing good about this problem.