I believe they work, I bought a couple diffusers for my cat who was having a "marking issue" when he got stressed. Since plugging them in I've had no more issues, he's even stopped scratching my couches
and Rizzo konks out pretty quick once play time is over. Of course some people say they don't work on their pets at all, lol. I think it's kind of like using lavander scented candles to calm yourself, for some it works, but for others it doesn't.
Congrats on finding such an easy fix to bedtime