Rough brake pull

its a steel cable and there is no grease between the the strands. you grease the cable so it slides within it's self on bends as much as you grease so it slides though the sleave. its a moving part for fuck sake any moving part needs some sort of lubricant to reduce friction.

the whole point of the ptfe liner is to not need grease.
the cable will slide equally well with or without grease.
grease is an option for waterproofing i'd say.