I would think that Canon does not intentionally sell fixed cameras and resets them, they have no reason to. There may be the extremely rare case that a camera is DOA, never is able to take a shot, gets repaired and has count of 0, but the two refurbs I have bought were in the low 100s.
So my questions is I guess, if you are legitimately asking this question, and not trying to figure out how to reset the number yourself... Is the physical condition of the equipment that bad that it causes suspicion for you? If so, why are you buying it? If instead the physical condition is immaculate to match the meter, why would you be doubting it has low count? And if you are buying equipment with a true 0.... why are they selling it as 'used'? I would let the experience in buying used equipment drive your guy and listen to it.
This is just a bizarre post. Not trying to troll you, just is coming across as fishy sounding.