Something like that... here's how that relay works:

31b = momentary ground to armature (steady ground burns them out)
15 = fused power in (used only for high-beam flashing)
81a = 12V to relay armature (jumper with 15)
56 = main 12V for headlamps
56a = output to high beams
56b = output to low beams

You can see it's meant to toggle one power input between two outputs, not to act as an on/off relay. It IS the relay used for OD in older 1800s that have a momentary switch on the steering column or later cars with a momentary pushbutton in the shift knob, which is no doubt why Rusty suggested using it -- but it does not work with a rocker switch.