Antiemetics are the most highly recommended drugs to take for SN. Without it, you'd need to stay conscious anyways so you can take a backup glass for when you vomit. Also vomiting can still occur even after taking an antiemetic, which is why it's recommended to make backup glasses even when you have antiemetics. It's also advised by some to not try to make yourself black out before SN's symptoms kick in, just in case if you vomit while unconscious. You won't be able to take the backup glass if you're still unconscious.
You can always take a couple of painkillers and benzos (only a couple of benzos, not too much to make you black out) to make the process more comfortable and less unpleasant.