Average voltage on an AC line is 0 volts. RMS is probably what you intended. But yes, Watt-hours are all basically the same for a given RMS voltage/frequency. We will ignore power factor, that would take a lot longer to discuss...
Just to be pedantic:
The electrons going through your appliances are almost entirely the ones that were in the wire of the appliance to start with. Some electrons may actually drift enough to have come from your house's wires. But for any significant number of electrons to physically be the same ones that were in the power plant is very low probability.
This may not seem obvious at first, but the reason is that the drift velocity of electrons is actually very slow relative to the currents typically used. In other words, a piece of wire has so many damn electrons that you don't really need to move a very large portion of them to get a large current. If we were all using DC mains, then eventually you would see electrons making a round trip. But with AC, as mentioned above, the average voltage is 0, so the electrons move back and forth, but not typically getting very far in either direction.
Also, a more direct thing to consider is that most electrical systems use isolated transformers. So literally, the electrons are not passing from the utility across that barrier (unless auto-transformers are used.) It is an energy conversion to/from a magnetic field.