Hi!
I can suggest you to ask about mucolytics(carbocystein, tyloxapol), medicines that break down or dissolve mucus. They can be used to treat chest condition with excessive and thickened mucus secretion together with expectorants.
There are some other things that can make elimination of mucus easier: increased intake of liquids, vitamins, physical therapy(vibrations, percussion and postural drainage).
Mucinex contains guaifenesin, one of the substances i mentioned in the previous post.
Waiting for your post!