silicone oil is widely used in the field of cosmetics. it is most practical to give an example.
if we look for a liquid foundation, we can find that the main ingredients are basically silicone oil. the several functions of silicone oil just mentioned are all reflected in this formula:
cyclopentamethicone: also known as d5, a volatile silicone oil with good skin feel and quick drying
trimethylsiloxysilicate: silicone oil film-forming agent, which helps the makeup to stick to the face, waterproof and sweat-resistant
peg/ppg-18/18 polydimethylsiloxane: silicone oil emulsifier, used to mix silicone oil and water together
polymethylsiloxane: generally used to treat various colorful powders in makeup to make them more soluble in silicone oil