RotateAround a player

I am working on making a zelda-type game, and i am trying to make a script to make the sword swing. I am using the transform.RotateAround function, and I can’t get it to work. Nothing happens. It deletes the sword clone after 1 second, but nothing happens before that, I don’t even see the object appear in my game window, when it does in the hierarchy.

void Update () {
			var P = (GameObject)Instantiate(sword,transform.position,Quaternion.identity);
			P.transform.parent = transform;
			// Spin the object around the world origin at 20 degrees/second.
			transform.RotateAround(transform.position, Vector3.up, -180);
			// Destroys the swords created after one second
			// of creation, in order of creation
			GameObject[] killEmAll;
   			killEmAll = GameObject.FindGameObjectsWithTag("Sword");
    		for(int i = 0; i < killEmAll.Length; i++){
    			Destroy(killEmAll*.gameObject, 1);*
  •  }*
  •  }*
  • }*

you should rotate P which is the sword.
also multiply rotation speed by the time the frame took to render (Time.deltaTime)
it should look something like this:

P.transform.RotateAround(transform.position, Vector3.up, 20*Time.deltaTime);