fresh pineapple and papaya (including seeds) are well known anti-parasitics. I tried just about everything in the book, and it's not that pineapple is necessarily the best one, it just came to mind. I think the way it works is just by digesting them since it is very high in bromelain. I tried many of the pill forms of digestive aids but nothing was as good as pineapple juice.
All the pungent spices are antiparasitic to some degree like garlic, cayenne, hot peppers. Apple cider vinegar is an excellent antiparasitic. There was a post about unsweetened cocoa powder being successful with liver flukes on the Liver Flush Forum .
DE (diatomaceous Earth) is also a good one. It's very individual so you just have to go through each one and see what happens, luckily these are all foods so you don't get slaughtered with the prices.