Its hard to follow your application. You have sodium chloride, granular, in bulk, and its clumped. I assume its clumped because its moist with water. Now you have to keep it dry -- but isn't that obvious? If you add more water, it'll dissolve. So you apply ultrasound. That's a pretty nebulous concept -- do you mean a sonication chamber, because that needs water to conduct the sound, like wise a ultrasonic lance, of the type used to disrupt living cells. How "un-clumped" do you need? For that matter, what is clumped and non-clumped, empirically? Would the salt not un-clump if just shaken vigorously, without ultrasonic vibration, just plain old, somehow less than ultrasonic, vibration?