I thought that was Rule 34.
Wade Boggs did it a couple of times-apparently had a pretty good knuckleball. He even toyed with the idea of transforming himself into a knuckleballer and starting a 2nd career.
I recall seeing Yankees catcher Rick Cerone pitch in the late innings of a blowout against Texas in 1987. He did a good job, striking out Texas pitcher Bobby Whitt, who the Rangers had chivalrously sent in to pitch hit. Cerone kept shaking off the signals sent in by his catcher with a big grin. He was enjoying the shoe being on the other foot for a change.