Wife bought the spray for ants, and sprayed the kitchen area. We sleep three rooms away from the area sprayed, but it irritated my sinus, gave me a sore throat, and a very bad headache. I would not use this inside a house, even with the windows open. The scent lingers for hours even after washing the surfaces sprayed. Essential oils in low concentration are deterrents to pests, but very irritating to mucus membranes in high concentrations. Just because they are "natural" doesn't mean they are safe to use and breathe. Radon is also natural, and a hazard.
Length of Use: Less than 3 months
Bottom Line: No, I would not recommend this to a friend