Kano AeroKroil Penetrating Oil and Bore Cleaning Solvent is Kroil under pressure. This is the handiest way to use this amazing chemical loosener. Squirts a thin stream of Kroil Penetrating Oil and Bore Cleaning Solvent up to three feet. Ideal for loosening frozen parts and threads. Kroil creeps below the fouling in your barrel, allowing you to knock it out easily with a patch or brush. For best results working with rusted or frozen gun parts, allow 24 hours for Kroil to penetrate.