The US army uses Permethrin to treat clothing as well. It works and it works for a long time. Be warned, however, some people are alergic to permethrin, and once the clothing is treated, its treated. To be safe, treat a single shirt to try first, so you don't have to get rid of a whole wardrobe. One of our Pilots had to run around in his physical fitness uniform for a week while the unit got uniforms and flight suits sent from the US.