Any light oil will work, so 3-in-1 and WD-40 are standard choices, but you could even use cooking oil if that's all you've got—you just need something that provides lubrication and blocks moisture. Besides Matt's tip about using a toothbrush, most light oils penetrate really well, so you can be lazy and let gravity move the oil through the coil, turn the gripper and then hit it from another angle. A little regular maintenance along these lines will keep your gripper from chirping and if you