In 1943, Cutler went to Indiana and tried infecting prisoners with germs gathered from local prostitutes and applied directly to the penis. This method didn't reliably infect the prisoners as well as actual sex, but that'd be crazy, right? Almost as crazy as not telling these volunteer inmates what was being put on the tips of their penises. Which is exactly what happened. So to be clear, John Cutler rubbed disease onto the dicks of confused federal prisoners, nothing much happened, and then he kept his job.
A Guatemalan physician, Juan Funes, extended an invitation for Cutler to come to his country and refine his dick science on the proud Guatemalan people. At the time, prostitution was legal in Guatemala and sex workers were required to visit a clinic twice a week. We assume to prevent the spread of STDs. In the name of science, John Cutler was about to put a stop to that.
There was apparently a double meaning when Cutler said he was "coming to f**k people."
Funes gave Cutler a list of prostitutes known to be infected with venereal disease, but Guatemalan lists are what you use to make tamales colados, not infect a population with syphilis. You see, John Cutler was a man of impeccable scientific method, so he created his own infected prostitutes. From a batch of eight uninfected prostitutes. He got the diseases into them via spinal fluid injections, which somehow seems both less fun and more dangerous than the traditional disease gathering method. And keep in mind, his experiments on preventing STDs hadn't even begun yet, and he had already personally given eight women STDs.