There's a reason that baseball has a banned foreign substance policy when it comes to pitchers and baseballs. Whether or not it gives a scientific advantage is one thing, but pitchers doctor their baseballs as they please because they -believe- it gives them a better chance. If pitchers think it's improving their baseballs, then they shouldn't get to use it.
Major league players need as much help as they can to get ahead of the competition. Mud can affect the weight of the ball as well as the pitchers grip. Special mud can have a different effect on the ball and the players grip than ordinary dirt found on the ground.
The special Baseball Rubbing Mud used by the MLB on every baseball guarantees top quality control and consistency. The mud's fine consistent texture guarantees that the pitcher will give the best pitch they can possibly give, vastly improving the game and the enjoyment of fans. Coming from one source on the Delaware River, you never have to worry about your grip when sending the ball over the home plate; the mud does it for you.
No, applying special mud to baseballs do not help to improve the performance of the baseball. This is just an old wives tale that many people who play baseball have bought into. It does not make sense to believe that rubbing a baseball with a certain type of mud makes the baseball better.