With the engine running, rub a bar of soap on the edges and back of belt and see if it quiets down. No it won't make it slip. Antifreeze, Armor All and other stuff makes the belt work like rosin on a violin bow and squeak. It's not a cure, won't last but good diagnostic tool. Fan blades will be really, really close to your knuckles but Hey you're a Ranger Man, Right?