If so, what were they proven to do? I've heard this sometimes confused with Lakhovsky's MWO. Are there any primary sources of his work on "healing machines" and coils/tubes that eradicate disease? Did he have any success, and were his results reproducible? Did he ever actually start a "Tesla Electrotherapeutic Company"?
Nervous and perpetually on the brink of exhaustion, Tesla began to experiment with the healing properties of his oscillators as reports began to filter in from around the country about its remarkable curative properties. These high-frequency "vitality boosters" would generate a "universal healing agent" that, when applied, would enable the body to "throw off all diseases," said Dr. F. Finch Strong. "Effects obtained [included] . . . increase of strength, appetite and weight, induction of natural sleep, and elimination." Other doctors reported the ability to cure tuberculosis.
"Tesla believes that electricity is the greatest of all doctors and says that when his laboratory was burned, nothing but regular daily applications of electricity kept him from sinking into a state of melancholia." "My high frequencies," he would say, "produce an anti-germicidal action." Thus, as part of his routine for a day at the lab, the inventor would disrobe, step upon his apparatus, and turn on the juice. A prickly corona would envelop his body and restore it to a most pristine condition.
from Marc Seifer's Wizard: The Life and Times of Nikola Tesla, ch. 18 High Society (1894-97)1
Tesla had a hunch that, since his high-potential, high-frequency currents could be passed into the body harmlessly, "these currents might lend themselves to electrotherapeutic uses." He experimented upon himself. When Tesla was struck down in the streets by a New York taxi, he didn’t deliver himself over to the medicals but dragged himself up to his hotel room where, in seclusion and with the help of his own electrotherapy, he recovered from his fractures and contusions. He never patented in electrotherapy but in 1891 began publishing his observations in technical journals, and seven years later we find Tesla giving a speech to the American Electro-Therapeutic Association in which he details with drawings the high-frequency apparatus he has invented for this purpose, which included a Tesla coil.
Tesla in his lab in New York Tesla also applied his resonance engines in bizarre forms of physical therapy. He created machines that flooded the human body with electrical currents and strong vibrations, intended to soothe aches and promote healing. And Tesla wasn't just the inventor of the "electrotherapeutic" device -- he was also a client. He reportedly became somewhat addicted to administering the treatment to himself, insisting that a session with the machine rejuvenated him on his long stretches of work without food or sleep. Tesla once let his friend Samuel Clemens try out the healing machine. The author is said to have enjoyed the experience tremendously, until the vibrations brought him a case of spontaneous diarrhea. Tesla marketed this invention, and the Tesla Electrotherapeutic Company was one of the few commercial enterprises of his old age that was marginally successful.
Other similar claims: