Schaff Piano Supply
Protek Prolube is a polymer spray lubricant which is designed for use on high friction areas like the keybed and keyframe. Works great for lubricating keypins also. Comes in a 4 oz spray bottle.
Keypins can be a primary source of excess friction in the key travel. Polishing and lubricating keypins is one way to help reduce the excess friction which can make an action feel sluggish.