Proof Bed Bug and Dust Mite Killer. Proof Bed Bug Spray Proof uses a lab-proven, patented mode of action to not only kill bed bugs on contact but also has the power to reach into cracks and crevices where bed bugs will hide and nest. The proof is even effective against pesticide-resistant bed bugs and eggs. Simply spray your suitcase and belongings, in and around your beds and living areas. The strong botanical smell lets you know that Proof is working and keeps working for days.