If you want liquid lubrication for it get some silicone spray that is made for rubber. Easier and better yet is to just use some corn startch powder. Since it's already dry it does not attract dust and dirt like liquid lubricants do. It is afterall what most rubber is coated with new, that's what the white dust is on most new rubber parts when you get it. It is also easy to apply. Just put a little in a can and apply with a clean cheap paint brush by dusting it on. It should get rid of the squeak, it's cheap and you probably already have some in your kitchen.