You can't get enough of the oil from eating pumpkin seeds. Better to use pumpkin seed oil, also killing isn't always what you want with large critters. Never mind that you need to worry about Genetically-Modified-Organisms or them being rancid as well as what seeds do to a damaged gut.
If pumpkin oil actually works for large critters then one would need to take it over a long time allowing the critter to slowly shrink in size giving up one segment at a time until it finally gives up completely...
Same as Bing Lang is used in TCM with large Ascaris infestations…