The guy just hooked up 1 receiver to 1 port and put a toggle switch to the red wire in order turn it on and off.

I could be wrong, but aren't the ports on the XBox master ports and your device a slave? It seems to me that if you have the ``data'' lines (I'm no good on USB terminology) connected to them all, when you apply power to the USB device, no matter from which port, or even an external power supply, it's going to be attached to each of those ports, which is not going to be what you want, I don't think.