It's not that unusual an idea if you consider the bacteria to be something of an adjuvant. Adjuvants are commonly added to vaccines to irritate the immune system into a more vigorous response, this could be seen as a more aggressive form of adjuvant to stimulate the immune system. Years ago I got told a story by a Croatian man who told me in his home village there was once a woman dying of cancer, the doctor visited her in what should have been her dying days only to find her working in the garden, the doctor went to the husband and asked how this could be because the last time the doctor saw the woman she was bedridden and on deaths door. After much prising the man said he couldn't bear to see his wife suffering so much and he decided to end her misery by feeding her rat poison in her food, to his surprise the wife started getting better until she was able to get out of bed and was seemingly cured. I thought this story was a load of cobblers, but it is interesting to consider the possibility that there might be some poison/bacteria out there that could trigger an immune response that would wake the immune system up to recognising, and dealing with, the cancer. I say good on the neurologists and the patients who agreed to this trial.