Is it possible to induce erysipelas to treat cancer, under the condition that the patient is to be given antibiotics to control the erysipelas?
Before any experimentation on humans, any treatment undergoes an extensive testing on animal models.

Besides, there must be some degree of confidence in the potential curative effect of a remedy in order to start experiments in the first place. An experiment like the one you describe would not be approved by your institute's animal ethics commission (there is such an unpleasant but important thing) unless you prove with some line of evidence and prior knowledge that the suffering of the animals is likely not going to be in vain.

It is now also customary to provide an official approval from the ethics commission during publication submission. [You would not need such an approval for flies or worms, but for rodents (which would likely be your first test object in the case in question) or primates you would.]