They are real and you very well might have them infecting your body. Many folks accidently find out they are hosting parasites while doing a psyllium based colon cleanse. The psyllium (and clay, in your case) literally traps the visible parasites and pulls them out in the stool.
Our Customer Service Department has gotten MANY a panicked phone call from folks who discover their parasite infection in just this manner! Most very quickly also become HUMAWORM customers!
In my opinion, it is better to treat for parasites and be wrong than it is to not treat for parasites at all.