There is a test called the "Entero-Test capsule" test. They put a capsule down your throat to pick up fluid/eggs in your throat. It is used for strongyloides stercoralis, which is what you might have.
I don't think you are trying a high enough dose of Vermox or understanding that eliminating parasites is a long term war. It is not a series of short battles.
Try googling Dr. Andreas Kalcker and looking at his protocol. He uses Vermox (mebendazole) and a lot of other things. His dosages are different and his timing is very different.
You can watch him on YouTube, especially at the Autism One 2014 conference.