In the case of a person who doesn’t send his knife to be approved by a Torah scholar, the shochet should be ostracized or, alternatively, removed from his position, depending on whose opinion or the specific circumstances. And “removing from his position” doesn’t stop there – he can’t sell his meat as kosher, and it is to be wiped with feces so that it can’t be sold to non-Jews either. Also: 2 new mishnayot – 1: On attempting shechitah with a rounded sickle with rounded serration – it’s a machloket whether that’s permitted. 2. On where precisely to slaughter on the trachea. Plus, if the slaughtering were done in a lower piece of cartilage, then it’s not kosher according to Rav or Shmuel, but then someone who should be their follower (or either) ate from that shechitah. Note the distinction between the leniency in the land of Israel compared to the stringency in Babylonia, and how one needed to navigate the various practices.