Hello - Castor oil is a very Old-time remedy for parasites. It was cheap and readily available - castor beans are very poisonious even fatal - and the castor oil treatment worked as a very powerful laxative/purge. It would flush out parasites from the colon just because they were caught up the tidal wave of stools being passed. It tastes FOUL and makes a person feel quite ill after taking it. I personally believe that the castor oil purges of old are why people gradually got away from parasite cleansing. Just think - a kid had to take that nasty stuff twice per year and it make him sick but it did it's very important job - that same kid got older and lived in more modern times - indoor plumbing, electrical lights and such and he refused to give his kids that nasty castor oil - his kids gew up and never even knew about parasite cleansing - and here we are today. MANY of my friends have just this life story.
The herbal formulas used today (like HUMAWORM) are far advanced from the primitive herbal treatments from the old days. Sometimes advancements are good! P.S. - A personal note here - I have taken castor oil many times in my life and I will personally never take it aggain. There are too many good herbs out there that do the same thing - only BETTER - and they don't make a person sick in the process.