I know there are a number of trick shooters who seem to have mastered it, but, like other trick shots, the best looking masse' shots are set up. An understanding of masse' dynamics can provide creative ways to alter rail shots in order to avoid interfering balls. A masse' shot is accomplished by tilting the axis of the ball so that it spins to the inside of the desired curve, and against the grain of the felt. The forward direction of the ball is accomplished by the horizontal angle of the cue stick. The amount and direction of spin is achieved by the vertical angle and the point of contact.
Force is also a critical factor.
To grab the ball well, the tip must be well chalked, and the ball hit thickly enough to provide table resistance. A masse' shot requires more friction between the cue tip and the cue ball than the weight of the ball alone will allow. This allows for maximum spin. When the ball settles back to the table the friction of the felt grabs the ball and the spin takes effect, pulling the cue ball toward the object ball. The masse' is an extremely complicated combination of physics that requires careful observation and lots of practice.