PetArmor for Cats takes 24 hours to dry. During this time, it will spread over the applied surface, and start its course of action to protect the cat against ticks and fleas. You can just wash your hands with a bit of soap and water if you end up touching or playing with your cat during this time. That way, you can get the medicine off of your hands. Try keeping the cat indoors during those 24 hours. Doing so will help you keep the cat clean while the medication continues its work.