Hello.
[ Answer 1 ]
I think that if you are located in person and executing this command on the computer/machine. I would think that a physical device would be less hassle. I do recall paying with one of these retro printer switches when I was a kid they have them for rj45 connections as well.
[ Answer 2 ]
Also You could turn on/off the network through the router by entering into the ISP modem/router settings and blocking the mac address temporally
[ Answer 3 ]
You can change the UAC level to low to turn off the prompt completely