I've found people who do this to be incredibly toxic, mostly because more often than not the opposite viewpoint has been disproved by a body of scientific liter

I've found people who do this to be incredibly toxic, mostly because more often than not the opposite viewpoint has been disproved by a body of scientific literature with which the "devil's advocate" is entirely unfamiliar. In that case, playing the contrarian is nothing more than trolling. When doing this, make sure the opposite viewpoint is at least as valid as the one you're arguing against.