Keesh is using headcraft instead of witchcraft. He uses his own strategy in which a bone of a whale with its tip is as sharp as a needle was covered with a blubber, or a fat of whale. if a wild animal ate this, it will melt and it will stuck in the animals's throat until they get weak, and there, keesh will take the opportunity to kill them with a spear.
I hope this may help :)
