Airway clearance technique are various techniques used to try to help clear thick mucus from the lungs. Some of these methods include: percussion, positive airway pressure, high-frequency chest wall oscillation devices, and chest physiotherapy among others. These techniques are frequently used in cystic fibrosis. Airway clearance technique are various techniques used to try to help clear thick mucus from the lungs. Some of these methods include: percussion, positive airway pressure, high-frequency chest wall oscillation devices, and chest physiotherapy among others. These techniques are frequently used in cystic fibrosis.