I live in South Florida and we have tons of gnats down here. I started using the REAL vanilla extract 2 years ago. It works to keep gnats from biting but they still buzz within inches which I find so annoying. Sweating in 90° weather requires I spritz myself down about every 2 hours if I'm lucky. Poor Traveler has them dive bombing his eyes and hasn't had much luck with the vanilla either.
In my opinion, vanilla is ok but it sure isn't all it's cracked up to be-at least down here in the 'Glades where bugs are in abundance and a whole lot bigger.
Lynn & Traveler