Putting the power cable in a Faraday cage will help, however the problem is any metallic covering if not earthed can transmit a fault between rooms, you can wire in SWA, braid or Ali-tube, and all will reduce the radio waves leaving the cable, however I still think in the main we can get away without such lengths being used.
I remember as an apprentice being given a radio to fit, I tried all the things I had been taught, chokes, capacitors, braid between bonnet and chassis, and still interference, an old mechanic said try another radio, I have got one here, see if that radio has interference, and on trying it did not have any interference coming through, it was the radio at fault not the way I had fitted it, and this I have seen repeated many times, so radio receivers will pick up any signal even if not on the frequency it is designed to receive on.
Does not even need to be a radio, I remember the Police car radio coming through my dads electronic organ, there is simply no point screening if the equipment is not designed to reject out of band transmissions.
So if your a radio ham and want to use QRP (word they use for very low power) and talk across the pond with 2 watt then maybe Ali-tube mains cables are worth while, but for most people it is not required.