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

Due to legal pressure in the United States, she operated the Century Nutrition clinic in Tijuana, Mexico , where she provided alternative cancer treatments beyond the reach of U.S. authorities.

In 1999, she was arrested in San Diego, California, based on a fugitive warrant from Indiana regarding charges of practicing medicine without a license.

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

She claimed that by removing these toxins and killing the parasites, any disease could be cured.

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.