According to the article in Popular Science Monthly 1931 by H. H. Dunn:
"Rife has devised a magnetic compass so delicate that it can be used to study the electricity and magnetism in living germs. He suggest that if the electrical make-up of certain dangerous germs is learned, it may some day be possible to destroy them in the human body by applying small doses of electricity. In no way, however, Rife makes clear, does this idea uphold the claims of medical fakers that they can cure disease by applying electrical “vibrations” to the body of a patient." (italics added for emphasis)
This would seem to indicate that, at least in the early days, Rife disagreed with the use of either:
(i) Audio frequencies, and/or
(ii) Direct application of electrical signals
His apathy about upholding this viewpoint after 1950 is understandable, since by then he had more than likely given up on his life's work due to government raids and lack of research equipment.