When I am a fascist, I warrant being chucked into the sea. As far as I'm aware, I am not a fascist, even though actual fascists like to call everyone they disagree with a fascist and call for their execution.

That's the real problem: Fascists copy tactics, and most people are shallow. If you can call someone a fascist and murder them, fascists quickly learn to call everyone who isn't a fascist a fascist and murder them. There will not be a deep investigation into whether a person really is a fascist.