Trying a medication that's proven effective to treat symptoms in some cases isn't the same as giving a placebo. One is regular medical practice and the other is medical research. People don't go to the doctor to participate in research, they go to get treated.
Recurrent skin infection? Experiment with antibiotics to find one it's not resistant to.
Patient on a ventilator? Getting them off will require experimenting with vent settings and periods of having them off the vent.