Mr. Rate: Would've been a bad job to take, though.
Nick Memphis: How come?
Mr. Rate: Whoever took that shot's probably dead now. That's how conspiracy works. Them boys on the grassy knoll, they were dead within three hours. Buried in the damn desert. Unmarked graves out past Terlingua.
Nick Memphis: And you know this for a fact?
Mr. Rate: Still got the shovel.
Bob Lee Swagger: I was kinda hopin' to keep one of 'em alive, but they were determined to kill you.
Bob Lee Swagger: Not bad for a poodle shooter with a makeshift silencer, huh?
Answer: If you cut a slit into them and squeeze when the ball expands back it creates suction. So they could have been used to clear away any blood or pus when cleaning the wound before stitching.