It's working, though. People are dismissing it as useless, and assuming the killer must've thought the same. The beaker also looks familiar, aren't they similar to what can be found in the study on the third floor? [She eyes the door to the smoking room, where the list of tools is attached.] I suppose we wouldn't know how the poison may be delivered and what the bottles could look like, if that was truly it, but it does say "assorted" on the list. I'd expect more bottles, and perhaps something more complex.

[...] Although if it's intended as a false lead, and only assuming based off of that hypothesis, then the alternative would be that it's planted to detract attention from the true second item, wouldn't it?