I don´t think eating herbs makes them more resistant, but it´s only my personal experience. Especiallly for that short of time it shouldn´t. Some parasites can sometimes move out from the intestines when they feel threatened, which has been described by other people on curezone. In that case they can move to other organs and do more damage.
Still I think the damage in general and overtime is greater when they are not treated! If you chew on pumpkin seeds even the big ones(if you should have some) can become paralysed for a few hours, and then it should be even safer to take some stronger herbs if you plan on doing so. Garlic and onions shouldn´t be a problem, hope you can keep up with that harsh diet though. Good luck and write about your experience afterwards please.