Baseball players use various substances to improve their grip on the bat. Here are some of the products that players use, according to the search results:

• Pine tar: Pine tar is a brownish-black, extremely tacky substance that is most commonly used by hitters looking to improve their grip on the handle of their bat. The tacky, sticky nature of the pine tar allows hitters to have a more “relaxed” grip on their bat, which can help in making better contact with the ball and getting more pop on contact.

• Bat Wax: Bat Wax is a wax-based grip aid that is used by rubbing the bar on the bat, similar to a normal pine tar stick.

• Grip Dip: Grip Dip is a pine tar and rosin solution that is spread on the bat using a wooden spoon that comes with the Grip Dip.

• Hitters Grip Spray: Hitters Grip Spray is a cleaner alternative to pine tar that offers premium gripping power and stays tacky even when wet. Spray goes on invisible, and can be applied either to the bat handle or directly to batting gloves.

• Spray adhesive: According to a Reddit thread, some players use spray adhesive on their bats.

Its unclear what exactly players are spraying on their bats, but it could be any of the above substances or something else entirely.