Originally Posted by NickBaer

How many of those 20k are Bots? Must be quite a few, if you have 100 unique/week. The rest already have CB cookies.

You might want to slim down your expectations, and implement some Bot Mitigation steps, in your .htacces file.

Most Hosting Providers have suggestions, if not outright code (list of Bots) to add to your .htacces file. Open a Ticket, and ask them for suggestions that work the best with their operating system