@bernadene24 I agree that details help. It sounds like you are making a valiant effort. I don't blame you for not wanting another bronch. Two other thoughts. If you have time, try waiting a few minutes between nebbing and doing huff coughing. Move around, take a walk, let it absorb.
Also think about your hydration status. If you're drinking a lot already and urine is light-med yellow, no need to increase and get over hydrated . If you know you don't drink enough, you could try that and perhaps mucus will be thinner. I hope you find something that works. It's so frustrating to try hard and not get samples.