Hi, Ales, this is just the thoughts of a non-scientist.

If what we perceive as gravity is simply the warping of spacetime, not a force, and black holes form as a result of extreme warping of spacetime, what is there to escape? The only way to lessen gravity in a BH is to take some of the mass out, or reduce its density, thus reducing the curvature of spacetime.

Perhaps you were thinking of gravity in terms of quantum theory, and were wondering about gravitons escaping. If that's the case, you'll have to wait for an answer from someone with more expertise. A theoretical particle mediating a force that is not a force, possibly escaping from infinitely curved spacetime, which may not be infinitely curved, is a bit beyond me.