Would someone who wants to do this use Google? Even if you google for how to block google from your website, you are likely looking to block Google from pages like phpmyadmin, not all of their website. I don't think this blog post would ever be a relevant search result in Google. Maybe if someone saw this comment, tells a friend, and $friend googles it... It just seems like a remote chance.
i.e. the only people that will (likely) see it are the ones that are already doing what you want.