Zapping vs. Pills

All -

Forgive my ignorance, but if a zapper is effective in killing all
stages of parasites in humans in all different areas of the
human body, then why would anyone repedatively purchase any
pills/herbs/etc... if a zapper will do the job?

To me, it seems like a single fixed cost vs. continueing expenses.
I suppose, the operative word is "if" - So, to slightly restate:

"Is a zapper 100% effective in killing all stages of parasites
in humans in all the different areas of the human body?"


Thanks, in advance, for the illumination -

MIKE