I used to make up a solution of dish soap and rubbing alcohol and hot water, with a scrubbing pad to take off stickum and grime from plastic. Or just use the rubbing alco first then wash. Coat with your favorite preservative. Has anyone used silicone spray on plastic rubber AR parts? Used to be a goto item for gear heads on car trim and so on. I haven't used it on gun parts, but wondered if anyone else had pros/cons.