There's a difference between letting a plant loose versus living creatures, though. The former is a lot slower and easier to track than the latter...

[Josuke, that was literally not the point, but of course he's stuck on this topic now.]

Wait. So they're just growing these plants for no reason or because it's festive...? [Oh right, the thralls and the Novices that are still human. That... would make more sense and of course that comes to him after he's already opened his mouth and shoved his foot into it.]

Oh right, the thralls and us... [There we go.]