Manual steering box OIL or GREASE ?

All I've seen have grease.Turning on the way back machine "1970's " the Dodge dealer where I worked if any complaints with the manual steer cars the service manager had us add STP to the box with a turkey baster.It did make them steer easier.Now those were new cars with fresh seals.If you add it to a 50 year old box I'm sure it will leak out the sector shaft seal.