Players cleaning ball marks off their bats?

[KGoldin]

TED WILLIAMS you can add to this list per The Kid The Immortal life of Ted Williams

[SEAFAN76]

Well you can't rub away the tiny dents made by the threads............

[CampWest]

Still a fairly common practice, but was way more prevalent the further back you go. I recall Ted Williams and Pete Rose talking about wiping down their bats with rubbing alcohol to keep them clean from dirt, debris, pine tar build up, etc. I've seen players do that more recently too. A lot of players used to bone their bats, which also removes ball marks including seam impressions.