Another option to consider is High Frequency Chest Wall Oscillation, which is done with a device attached to a wearable vest. This can loosen otherwise adherent mucous secretions, allowing them to be expelled by coughing.
A summary of results is attached. A discussion with your pulmonologist should determine whether it would be a useful treatment modality for you. The downside is that it is more expensive than the average trumpet (maybe even as expensive as a high end boutique model), but the upside is that insurance often covers it, unlike the boutique trumpet.