Zerret Applicator

The Zerret Applicator is a device consisting of two conjoined plastic spheres (frequently compared to a dumbbell) containing a tube of a substance called "Zerret water" that, when held with one hand on each sphere (and legs uncrossed) for a prescribed time period, would allegedly generate "Z-rays" to "expand all the atoms of one's being", purportedly balancing life forces and inducing relaxation to cure the user of a variety of ailments. It was invented and manufactured by William Ferguson, with sales managed by his associate, Mary Stanakis, both of whom were ultimately charged and found guilty of "sending a misbranded article interstate" for their troubles; at trial, a government chemist tasked with investigating the device found the "Zerret water" to be ordinary tap water.

The device was one of several singled out for denouncement as fraudulent in a Food and Drug Administration (FDA) public service announcement video aimed at senior citizens, in which actor Raymond Massey states that "there are no z-rays."

Resources

 * FDA PSA video featuring Raymond Massey, c. 1950: https://archive.org/details/fda_quackery_psa