To add sensitivity to the hits, they shoulda pulled the guy's wiener and balls to the back, and then commenced with the batting practice.
-or-
Do the battings in a no-kidding, real batting cage. Ass cheeks used in place of a catcher's glove. No slow pitch softball speed, either - semi-pro league speed would be enough. Ball is pitched, hits "glove" (ass), then followed by the bat.