In the olden days naughty boys often dipped pigtails in what?

Oh, dude, in the good ol' days, naughty boys would dip pigtails in inkwells. Yeah, like, they thought it was funny to mess with people's hair and ruin their writing supplies. Can you imagine the chaos if that happened now? Like, "Oops, sorry, I just ruined your hairstyle and your pen!"