Actually I've tried a Clear Lungs liquid formula (though I don't think it was extra strength) with CS for nebulizing. For whatever reason I didn't feel any results to speak of beyond nebulizing CS alone - but of course that's subjective.
I even tried clear lungs, CS and lobellia together. But for me it was adding the Mullein that seemed to really speed the recovery. The last two times with CS, Mullein and lobelia I recovered from pretty nasty bouts of bronchitis in just a few days. Antibiotics usually took a minimum 2 weeks. And since stopping Antibiotics , my usual bouts of bronchitis have also been occurring fewer and further between.