sir artpogi::: tama ka rin. :D
i had my servo assembly replaced at the casa because the gears looked delicate and upon advise of my father, have it calibrated.
I believe that if the servo kit is properly installed, it woudn't need cleaning because the gears on the servo are inside and aren't exposed to the elements. But then again sir, it's just me.

Right again sir, the servo controls the engine when idle. so you would know that the servo needs replacement when your idling is erratic.