I remember reading a long debate about switch lubing and coming away with the idea that there is some benefit, but that the lube eventually all wears off down into the switch leaving you with the same scratchiness.
I've never lubed my switches, but did once lube my cherry stabilizers. It was quite a revolutionary experience and I have now gone back and lubed all of the stabilizers on all of my boards. Perhaps I need to try switch lubing.