Too ill to treat?

At what point is a person too ill to treat? I have 8-10 large parasites (over 6"'s) that the meds cannot touch. Ive killed hundreds and hundreds of small ones over the years but no luck with the large scattered ones. I guess i cant stop treating or new ones will hatch. Has anyone tried electricity from a doggie fence or something like that? Zappers are getting the LG ones either.