Right this might make me sound like a bit of a lemon but here goes.
If you got an unpressed cleft, and hit it with a mallet lightly at first, getting harder as the fibres compress. Would it every get to the state of a pressed and knocked in cleft?
Also and again plonker time here, would it not reach the sort of natural pressing point? I know that presses exert tons of force onto an area, and knocking in would take weeks but would it work in principle?