Supposedly they can become resistant to it, it's why Humaworm says to wait 90 days between courses to avoid that.
I don't think humaworm is enough to get rid of a bad infestation, which is why I pair it with a lot of other things that you might want to try if you haven't.
For the cayenne/tumeric you might want to buy some empty capsules to put them in and start taking them regularly throughout the day, and especially with everything you eat.
Have you tried coffee enemas? I use to think they were just over hyped nonsense but they actually help a ton if your liver is over taxed. I didn't even realize how badly mine was until I first tried a coffee enema. Now I consider them essential.