Silicone is used in a variety of automotive applications, in body lotions, make-up and hair care products. It leaves a thin, slippery film on anything it touches. Silicone oil is not very water-soluble, and spills on fabric can require repeated cleanings to break down the oil and wash it away. Fortunately, plastic is not as porous as cloth. Clean up oily plastic caps, car parts or utensils in one attempt by using a degreaser and plenty of hot water.
Wipe up excess silicone oil with a paper towel, leaving as thin a film on the plastic surface as possible.
Buy a liquid degreaser at your local home improvement store. You'll find many types there, from chemical solvents to organic degreasers to dishwashing detergent that contains degreaser. If you're concerned about the environment, read labels on organic solvents to find one that contains active microbes that "eat" oil.
Apply the degreaser according to the label. For plastic, a simple spraying will do the trick. Give it a few seconds to work, then wipe dry with a clean, soft cloth.
Test the plastic with your fingers when it's dry. If it still feels slippery, reapply the degreaser. If you're using a degreasing dish detergent, let it soak in hot, sudsy water for 10 minutes. Rinse thoroughly, and let air dry.
Clean up silicone oil spills quickly, particularly on floors or handrails to prevent accidental injury.