The article clearly states that the parasites in this case cause damage that results in an immune response that promotes tissue repair and reduced inflammation. it may be more accurate in this case to state that parasites cause an immune response that promotes healing. The immune response that is cited is a Th2 response. In a body that already has a dominant Th2 response, this probably wouldn't be beneficial. Candida can manipulate the immune response towards a Th2 dominance, which favors the spread of candida. ATh2 response is also associated with allergies and asthma.
If someone had an overly dominant Th1 response, this could be a beneficial therapy.