I saw that you didn't get any responses -- maybe no one is inhaling GHS around here. If you look at the Cystic Fibrosis Foundation website, you will see they are running 2 studies. One is with inhaling GHS and the other is taking oral NAC capsules (which is a pre-cursor to Glutathione). I personally take the NAC capsules and believe that it in part has helped me not to culture Pseudomonas or Staph in the last several cultures (I always culture it). I have been on it about 2 years.
For me I would rather take oral NAC than spend more time nebulizing, and I also would not inhale something that was not made in a special respiratory lab like all other inhaled meds.
So the question of exactly what the effect of these supplements are is going to be revealed in the near future and all the guesswork will be removed.