"Lubricating(nl)To keep the pump operating smoothly, follow your monthly vinegar flush with a dose of oil. The best choice is a lubricant intended for marine toilets, but you can also use mineral oil. Oil lubricates the pump wall and helps to keep internal rubber and leather parts supple.

The usual treatment is to let a little water into the bowl, pour in a couple of ounces of lube, and pump this through the toilet. This method is adequate, but less than ideal because it lubricates only the discharge side of the pump. To also lubricate the intake side, disconnect the intake hose from the closed seacock and pour the oil into this hose. Pumping the head will pull this oil through both chambers of the pump.

While you are servicing the head, lightly coat the piston rod with Teflon grease. This will prolong the life of the piston-rod seal."

Some recommend silicon grease, since it sticks and is non corrosive. Like multitudes of others, I actually use the cheapest cooking oil I can find (not recommended to pump it into your holding tank). And never again SuperLube (although I use it for lots of other stuff).