Are you saying that “quarantining + something not known to have an effect” is better than quarantining alone? Why?
If I had some disease and hundreds or people told me that spinning around in circles for a few minutes would cure it, I might think it illogical and silly, but in my mind it would be irrational not to just try it when the alternative treatment is nothing. Perhaps that is deeply flawed thinking *shrugs
If you believed in that cure then it would be likely you'd treat the disease with less caution and be more likely to catch and spread it due to believing in a fairy tale cure. You also may avoid getting actual treatments due to believing you already had an effective treatment. Both of these were huge issues with ivermectin.
Knowing for certain that it won't hurt, would require studies to be sure. Taking some drug while being sick could just as well make it a lot worse.