Hulda Clark -

Clark’s central thesis, popularized in her book "The Cure for All Diseases," was that every illness—ranging from diabetes and AIDS to cancer—stemmed from two factors:

The Federal Trade Commission (FTC) took action against various companies marketing "Zappers" for making unsubstantiated medical claims. Legacy

Despite the lack of scientific validation and intense criticism from medical watchdog groups like Quackwatch , Clark maintained a loyal following. Products based on her designs continue to be sold through independent retailers, such as the Dr. Clark Store , which was carried on by her family and associates after her death from multiple myeloma in 2009. Dr. Clark Store, Inc OFFERING STATEMENT - SEC.gov

Clark is famous for inventing the , a hand-held electronic device that she claimed could kill parasites, bacteria, and viruses by delivering a low-voltage, high-frequency current through the body. Her protocols typically involved: The Zapper: Daily use to "electrocute" pathogens.