One thing that I remember being told by a relative old-timer who was in charge of the work shop at WheelSmith in Palo Alto was that my Stronglight 93 crank tapers should never be greased.
I wasn't even there that day for any crank-related reasons and had not mentioned the cranks, but as he looked over my bike that's what he decided to tell me.
I knew that I had oiled the spindle taper upon assembly but chose to remain quiet. He seemed to be speaking from many years of actual experience working on bikes with those cranks so I respected his opinion, but as a lightweight (who spread his mileage among several bikes) I wasn't much concerned about it. I've installed model93 cranks dry on the spindle ever since though.