Anyone use it? I would assume it's almost impossible to clean from the cases? Found this online: The very best case lube for bottle neck rifle brass is 100% synthetic motor oil. Castrol Syntec 5W20 works very well, but other viscosities would probably work well too, as would the full synthetic (not synthetic blends) from other manufacturers such as Mobile-1 or Amsoil. Pour 1/8" of full synthetic motor oil into the cap. Dip the case neck, so the oil coats the open end of the case neck approximately 1/8" on the inside and outside of the neck. It's important to lubricate the inside of the case neck so the expander rod won't stick or drag so much that the brass is stretched and work hardened which would soon result in case neck splits. Use your finger to wipe the oil off the outside of the case neck, which will leave a very thin film on the outer case neck. Wipe that oil down the outside of the brass. Avoid case lube on the shoulder (the angled portion of the brass below the case neck and above the body) because oil on the shoulder can result in hydraulic dents on the shoulder. Hydraulic dents are caused when the resizing die pushes the incompressible oil into the brass. Hydraulic dents will be pushed back out when the round is fired but will result in work hardening the brass and shortening its life. Resize the brass. Tumble the brass after resizing to remove the resizing lube and clean inside the primer pocket, prior to reloading. The advantages of 100% synthetic motor oil: Very inexpensive. $5 per quart for a lifetime supply. Readily available at auto parts stores and automotive sections of department stores. Fast - smaller calibers need lubrication only every 10th case! Easy to use. Not as messy as sprays and sticky waxy lubes. A small amount is needed, so it lasts longer and doesn't gunk up the tumble cleaning media. Extremely effective. Demonstrated repeatedly lubricating only every 20th .223 case! The only lubricant that allowed resizing oversized .50 BMG brass that had been fired in a loose chambered machine gun.