I am a sufferer in good standing, since mid-80's if I remember correctly, and just got smacked again with the latest round of clusters.

Docs being how they are with pain meds, just left me out in the cold, I qoute "you can take the Imitrex, or not, the doctor won't prescribe anything else"

When the headaches hit (8 times in the past 2 weeks, including two trips to the emergency room), my right nostril closes up. 

Occurred to me that if the nostril wasn't closed, I might not get the headache, so I held it open when I felt it coming, and breathed deeply thru my nose.

No hard evidence yet, but I think I dodged two headaches this way.

Anybody else played around with airing out the sinuses as a cure?

Been there, done that, had a doc that would prescribe Stadol.

That worked very well, when my headaches were at least three days apart, but when they became daily, you are correct, addiction, tolerance for the med, and abuse became a problem.

As you say, rebounds are hell, and the addiction is worse.

Your nostril closing up (probably on the side of your cluster) is the result of the CH and not the other way round.

Check out O2. Makes a world of difference.