I had one pullet that wouldn't lay with the fake egg in the nest at first...so leave one nest empty.
Eventually they'll get the idea.
New layers can be quite goofy acting, they don't know what they are doing at first and can be confused and anxious, it can take up to a month or so before they...
I wouldn't put a bunch of aromatics in a closed area like a nest....could irritate the chickens delicate respiratory system.
Nests shouldn't be stinky anyway...if they are pooping in nests you have another problem.
For a pest deterrent, this is about the best place to use DE...I like straw...