And I don't think that it is a harsh drug, I took it with no problems and it did help a former poster who had something nasty. Maybe you could combine it with some good herbs. I am taking Diarex (oleander plus other herbs) http://www.himalayahealthcare.com/PRODUCTS/diarex.htm
along with Allibiotic from NOW and Digestion blend from Solaray and seeing some results.
The other issue may be the need for lumicidal drugs such as Diolaxinide Furoate, or Furazoline (sp). If you cannot kill the cysts hiding in the lumen then they will repopulate thus continuing the infection. Iodoquinol is another lumicidal drug but I am not sure if this is prescribed for crypto, it is used for d. fragilis.