I wonder if you can have a chain of "invisible" links on your site that a normal person wouldn't see or click.
The links can go page A -> page B -> page C, where a request for C = instant IP ban.
We do something similar for ssh. If a remote connection tries to log in as "root" or "admin" or any number of other usernames that indicate a probe for vulnerable configurations, that's an insta-ban for that IP address (banned not only for SSH but for everything).