Yes, the work of Hulda Regehr Clark is frequently grouped with Royal Rife in the alternative health community. Her theories are widely considered the modern continuation—or a specific variation—of the frequency-based paradigm that Rife pioneered.

While Rife focused on a "Beam Ray" device to destroy pathogens, Clark’s work, most famously detailed in her book *The Cure for All Cancers* (1993), introduced the **"Zapper"** and a holistic philosophy centered on parasites, solvents, and environmental toxins.

### The Overlap: Frequency and Pathogens
The core ideological overlap is the premise that all living organisms—including pathogens like bacteria, viruses, and parasites—have a resonant frequency. 
*   **The Mechanism:** Both Rife and Clark argued that by applying an electric current or frequency to the body, you could disrupt the biological integrity of these pathogens, effectively killing them without harming the host.
*   **The Diagnostic Tool:** Clark developed the "Syncrometer," a device she claimed could detect the resonant frequencies of various toxins, parasites, and organs within the body. This is structurally similar to Rife's early claims about frequency identification.

### The "Clark Protocol" Divergence
While Rife focused heavily on the electromagnetic device itself, Hulda Clark expanded the scope to include a specific lifestyle and detoxification regimen. Her claims were often more sweeping:
*   **The Parasite Theory:** Clark famously posited that all human disease—especially cancer and HIV/AIDS—is caused by a single human intestinal fluke (*Fasciolopsis buski*) combined with the presence of isopropyl alcohol in the body.
*   **The "Zapper":** Unlike Rife’s high-frequency beam ray, the Zapper is a simple, low-voltage device designed to be held by the patient. It typically sends a square wave pulse through the body. 
*   **Holistic Detox:** Clark emphasized that "zapping" alone was insufficient; patients had to remove chemical solvents from their homes (shampoos, soaps, toothpaste) and perform intensive herbal cleanses to purge the dead parasites and toxins.

### Mainstream Scientific and Legal Reception
Like Rife, Clark faced intense scrutiny and legal trouble that solidified the mainstream medical establishment’s view of her work as fraudulent.
*   **Legal Scrutiny:** Clark was arrested in several states for practicing medicine without a license. In 1999, she was arrested in Indiana, though the charges were eventually dropped due to jurisdictional issues and her move to Mexico.
*   **Scientific Discreditation:** Mainstream medicine—including the American Cancer Society—categorically rejects Clark’s theories. They point out that:
    1.  **No Biological Basis:** The idea that all cancers are caused by a single species of parasite is scientifically unsupported and contradicts the complex, multifactorial reality of oncogenesis.
    2.  **Lack of Peer Review:** Her research was never published in reputable, peer-reviewed medical journals.
    3.  **Experimental Failure:** Independent investigators have consistently found that her devices (the Zapper and Syncrometer) perform no better than placebo and are based on electronic principles that do not interact with biological organisms in the manner she claimed.

### The "Suppression" Narrative
The reason you often see them linked is that both figures are viewed through the same lens by proponents: they are seen as "outsiders" who were silenced by a medical-industrial complex that prefers high-cost, recurring revenue models (pharmaceuticals and surgery) over simple, low-cost, or home-based frequency healing.

Where Rife is seen as the "founding father" of the frequency movement, Clark is viewed as the "democratizer" who took those concepts and turned them into a home-based, DIY health movement. From a critical perspective, both are categorized as peddlers of "radionics" or "energy medicine" that lacks any verifiable foundation in biology or physics.