Sue, sputum production is my problem too. What I do recently I use sodium chloride 7% and a vest at the same time. I noticed this is the only time I produce clear stuff which I cough up, not even huff coughing because mucus comes - if there is any. Then after 15 -20 minutes I attach aerobika to aeroclipse and when sodium chloride is finished I stop the vest, remove aeroclipse and continue with aerobika only. Usually it’s the end of producing anything to cough up but I do it anyway with hope it helps somehow to stay stable. I think dr Shane is right about using sodium chloride alone but I shake myself with the vest too. You never know what day what works. But I hope you will be able to spit something. The day before planning to get a sputum sample I get really anxious if I can produce enough or at all. So I hope you are lucky today. My best