The bottle only says to spray but doesn't say to ONLY spray. In my research of my recent Gnat issue at 5 weeks into flower I have read that bacillus thuringiensis will kill the larvae. All references online to killing gnats via BT refer to a BTI mosquito dunk. I don't know what that is and I have an 8oz bottle of Safer Caterpillar Killer. I called Safer and the tech knew nothing and was obviously out of his element. Can I feed with the Safer BT Killer and has anyone used it to kill Gnats?