You really want to use water soluble lubrication for shaving. Vaseline ( and many pre-shave oils) is not water soluble, making it difficult to wash off your blade or your face. This is why pure glycerin is so ubiquitous in shaving creams. I buy it by the gallon and use it as a pre-shave lubricant before applying my favorite cream. I pump about a quarter size in my palm and apply to my wet face. You can feel how slick it is. The pure vegetable grade is used as a sweetener - bonus taste when you get it close to your mouth.