From the Manufacturer:
Some research shows the hypertonic (2.7%) or more concentrated solution may help reduce nasal congestion better then isotonic (0.9%)solution. The theory is that hypertonic or higher concentrated salt solution will draw the water out of the congested tissue, reduce the edema or swelling and open up the nasal passages and sinus openings to allow for better drainage.
NasaMist™ hypertonic should not replace SINUS RINSE™ Nasal Rinse Kit for the purpose of true large volume (4 to 16 0Z.) nasal irrigation at a time. Please note that therapeutically effective large volume irrigation for daily hygiene cannot be performed by saline sprays. In view of this for large volume irrigation use SINUS RINSE™.