I used to put small coins on the terminals til they got super hot, then drop the coin on the desk in front of them. When they go to pick it up, it burns them. Peak comedy.
They prob wouldn't get shocked but the ring and battery will get very hot very quick as there i pretty much no resistance wich means there is a lot of current flowing.
Someone else in the comments claimed to have calculated a resistance of 0.2 ohms.
I=U÷R
9V ÷ 0.2Ω = 45A
45 amps is a lot of current to flow through a nose ring. I don't know how much that is in heat but i'd expect you to get burned from it
Dry skin is hundreds of thousands of ohms. Even wet skin has pretty good resistance. When you touch a 9v to your tongue, you're starting to mess around with lower resistance flesh, it is definitely not a comfortable thing to do.
The metal ring doesn't do anything to move more electricity into your body, but it soaks every electron the battery can push and turns it into heat. Best I can figure it would amount to a few watts, which would be toasty if you were holding it between your fingers. The septum is a thin piece of flesh, I think it would sauté pretty quickly.
If those are separate pieces of metal embedded in the skin, they will feel something. If it’s just an incomplete ring, it will draw so much current that the battery voltage drops too low to feel anything but the heat.