Castor oil and cod liver oil both were used by our grandparents (ok, maybe great grandparents) as deworming agents. They kill parasites *IN THE DIGESTIVE tract* only. Back then, pollution wasn't so bad and most parasites stayed in the digestive tract, so it actually helped quite a bit--but now, very few parasites stay there. They can eat their way sooo easily with the toxins whacking on our immune system.
You really need a zapper for the ones in your body--or get started on turmeric--it will take a while, but eventually it'll build up enough to start killing those outside the digestive tract too. But castor/cod liver oil would help break up that ball, although the worms would just crawl out of your digestive tract--not helpful.