Does any practical RC circuitry exist which will perfectly cancel out a pole?
No.  You may be able to get close, but not an exact cancellation.  That's why you need to be careful trying to cancel a 2nd pole (the one that causes the gain to roll off at -40db/decade) or the pole in a second order filter because if you miss, you could still end up with 0 deg phase margin and a possible oscillator.