https://laughingsquid.com/baseball-rubbing-mud/
1440 shared some facts about the specific rules applied to regulation baseballs and the special rubbing mud that's applied before each game.
rubbing mudnew jerseyspecialapplied
https://www.inquirer.com/phillies/pitchers-foreign-substances-lena-blackburne-mud-baseballs-20210618.html
MLB will start suspending pitchers 10 games if they're caught using foreign substances to grip baseballs. So the only help they'll get is from mud that's found...
lena blackburnerubbing mudforeignsubstancemlb