Mad Monk is right on. If you let the bottle stand, you will see the water on top and the small amount of soluable oil on the bottom. That is why they say to "shake befor using". I looked at a ten year old bottle in my shop and the oil was gone! I quess somehow, it evaporated. Hot water for cleaning followed by bore butter while the barrel is still warm has kept my barrels looking like new. At least on the inside.