Just keeping the conversation within context of Beck Protocol, the Mag Pulser is said to be beneficial for reachig the deeper recesses of the body such as the lymph nodes.
It does seem worth notiing that people in general are aware that their body has depth to it, and that certain activities inside the human body occur at varying depths compared to other activities; some activity occurs closer to the surface, other activity occurs deeper within the body. People also are generally familiar with the idea that any of the various bio-electro tools & methods are said to be more or less effective with respect to depth; some methods are said to be better at penetrating deeper while other methods are generally known to not penetrate very deep. As far as fully understanding and appreciating this depth situation, there does not seem to much in the way of exactness defined to help the lay person know how effective any one of the given bio-electro methods/tools will be.
As far as I am aware, the term "zapper" as it relates to any of the various electric gizmos loosley categorized as "Zappers", such as Hulda Clark , Parazapper, Zapperplans, Don Croft, etc, is not formally and directly associated with the methods of the Beck Protocol.
Indirectly, some people use the term "zap" loosley to mean the disabling/killing of parasites through the use of the wide variety of electro methods that broadly encompasses Beck Protocol, Zappers (Clark, Zapperplans, Croft, etc), Rife "frequency", Crane, Ultra Ray, PAPIMI as well as a whole host of other electro-based methods.
If the conversation strays to a broader context that takes in Zappers, which unto themselves can be their own separate but broad topic because of all the different brands of Zappers that have appeared, you may find some who say this brand of Zapper or that brand of Zapper might help with debris clogged up in the lymph system.