mention a plausible sounding skill that doesn't exist as a requirement for the job, ask about specific experience, and reject applicants mentioning it. it's the same level of sophistication as a display:none honeypot field on a form. no need to be such a tool.
Why would any real qualified candidate apply to a job posting like that? I'd look at it, say "this is nonsense/some kind of scam" and move on. You're basicaly just ensuring that you'll only get applications from AIs, idiots, or extremely desperate individuals.
Remember, good candidates are evaluating you as much as you are evaluating them.
