Is it possible to block specific searches aimed at a specific website?

[MikInMontague]

I have been struggling over the past year or so with a constant search hit from Google. Seems someone (or some thing) is hiding their activity behind a Google search and just slamming one of my sites. I figured out how to block them a few months ago based on their Japanese Kanji script searches that were very long, but it appears they're baaack! Here are two examples from earlier today:

I can easily block these by adding square brackets to my query_string block, but it's a game of whack-a-mole.

And, they're hitting my site's own search results page -- for just ONE of the sites I host.

Any advice?

Thanks, Mik