Add Patchouli Oil To Keep Mosquitoes AwayPhoto by Rapha Wilde on Unsplash a close up of a mosquito on a white surfaceWould you stick your arm in a mosquito-infested cage for three hours with nothing but patchouli oil? According to the American Chemical Society, adding patchouli oil to unscented cream keeps mosquitoes just as well as DEET. Three Hours No Bites with Patchouli OilResearchers had subjects coat their arms in either the Patchouli Oil, DEET lotion, or nothing. The patchouli lotion and DEET were both effective for up to 3 hours at the same concentration. So just like the harsh chemicals, the natural oil can get the job done as well.