I agree with the consensus about poking the wire in the hole and wrapping it clockwise around the screw terminal.
I found a couple of Cooper/Eagle 15A resi grade receptacles on the shelf that are probably like 7-years old and they only have that hole on the grounding terminal. Same thing with the Cooper 20A single receptacles I have here. I also noticed that the 15A P&S toggle switches seem to have it on the grounding terminal as well, but I really can’t say that I recall ever using it on any of them before though.