It is possible to avoid almost totally the electromagnetic emissions of a power cord by manufacturing it with a suitable electric shield. These cables should replace the black rubber cables provided by commercial products.
A shielded power cord has a braided copper shield around the wires, and the wires are tightly twisted. The braided shield is soldered to the ground wire near the plug. The whole cable is furtherly covered by a braided nylon tube to protect the inside from dirt and wear.
The electric shield, connected to the ground, blocks almost all the electric field produced by the wires under voltage.
The electric shield of such cables can also be made of aluminum foil, or metalized mylar foil, with almost the same results in terms of electric shielding.
Measured electric field around shielded and non shielded power cords
Electromagnetic emissions from power cords
Comparison of different shielded power cords