Have taken NAC (N-Acetyl Cysteine which thins mucous, but it kind of makes my mouth very dry at night. Currently I drink mullein tea, which thins the mucous somewhat, but isn't as drying as NAC. I take Boswellia which is an anti-inflammatory. I think it helps keep the mucus production in check somewhat. If I get an actual flare, I will probably go back to NAC or Mucinex during the flare.