Always looking to be a blessing ;)
However, you can achieve the same effect by increasing the motors input voltage. Which the demonstrator is doing with his device. But the life of the motor would be shortened. You have to strike a balance between efficiency and cost. Most residential are resistive nature, which this presentation doesn't address. Where does he get the power to run his device? It still comes from the transformer outside the building......Just my two cents worth. Not all is as it seems...