certainly can become resistant. That is why it is important to kill them the first time. Those that aren't killed become stronger. Zap em while you do a parasite
cleanse. You can do many things to help the cleanse along. Eat raw garlic, eat cayenne, eat raw pumpkin seeds. When I was taking Paragone I ate raw pumpkin seeds. My little dog begged for some of the seeds, so of course I gave them to him. He ate them two or three times a day with me. He passed parasites
GSE helps get rid of them and so will oil of oregano. I do not know if you can take either or both of these with a parasite
cleanse, but you can take them before or after.
Most herbs work best if used for only a couple of weeks. Switch off to another one or none for a few weeks.