myfriendsam: Few things for the ppl who don't follow immunology not just you.
First you can't "boost" the immune system with parasites by "natural means" since they control your complicated interleukins to some degree (not in your favor) and active Tregs which put a break on your immune response to name few things here.
Second the body never learned to get rid of them it learned to live with them even if it did matched the parasite sophistication one day you would die since we were constantly infected with them = massive internal damage on daily basis = sepsis which will kill you on it's own (not all but parasites secrete chemicals to block sepsis to keep you alive with them).
Third how do you know that you killed all of them to begin with before even talking about re-infection?
Fourth anything else (diet, exercise, etc) help your immune system to be more efficient and not spend a great deal of resources dealing with unnecessary inflammation. This won't however get rid of them.
Lastly larva might get injured and may die but it's not white and black here reg your immune response since parasites have very strong armor and IGE don't really bind to alive ones as good for your specific WBC to do the dirty job even if the immune system would be switched on in your favor with no massive damage to you. Adults do die but the eggs turn into larva and later into adults.
Your body main mission is to keep you alive with them for as long as possible and repair the damage daily reg helminths. It only goes after them on their cycles and when the numbers get out of hand provided that everything else is working correctly but even here it is aimed at just controlling them.
Hope this shed some light on this very complex issue.