A casting process that employs a collapse-prone core is disclosed. The applicator includes an outer surface, and an inner surface opposite the outer surface. The scaled LED waveform is then transmitted to an LED to cause the light emitted by the LED to pulse at a variable brightness. The present invention also encompasses an apparatus that comprises a sensory stimuli device, a mass audience area substantially within a space for reception of the sensory stimuli device, and computer hardware and software. The bushing also includes a sleeve having an threaded inner diameter that is threaded onto the shaft such that the attachment flange is clamped between the inner member and the sleeve and a bottom end of the sleeve is suspended over the LED. Also provided is a substrate coated with the plurality of ultra-fine metallic particles obtained in accordance with the method of the present invention.