For example, where the liquid flowing within the chamber comprises an aqueous solution, and more particularly water, and the ultrasonic frequency at which the waveguide assembly 101 is to be operated (i.e., the predetermined frequency) is about 20 kHZ, one or more of the agitating members 137 are suitably constructed to provide a vibrational displacement of at least 1.75 mils (i.e., 0.00175 inches