I can't imagine they are resistant to 30 days of using herbs, your liver and system would have to be pretty poor health to not be able to kill these creatures in my opinion. Normally they run out or up and out on the first doseage and they are rare to begin with in large adult stages a foot long.
A liver flush (3 or more) would show who is living in your organs. 1 drop of oregano oil is potent, several drops has produced a pile of ascaris worms out the bowel in the Amish Clinic. Using 30 drops in 30 days should have ran them out along time ago.
There must me much more to the problem and you will have to do more until you find the solution. zapping may hurt their feeling, but they are large adults and zapping has no effects on adults that I am aware of, if you use enough electricity to kill them, you shocking your body allot.