Other trolley systems also used shoes at the end of the poles and greased. I spent many weekends of my youth at the Ohio Railway Museum where I remember them greasing various locations, perhaps once a year. At ORM they did this by hand from a line car. A line car is one that had been purpose built or a rebuilt car of other use into one that had a insulated (ie wood) platform on the top where they could work on the overhead without turning off the 600 volt power.
(Eastern Michigan line car 7763, circa 1970, photo by Dave Bunge)