Is this supposed to be humor?
From a technical standpoint it strikes me as reasonably plausible. The inductance and/or resistance of the long extension cord(s) would help to isolate the system from sources of electrical noise which may be present elsewhere in the house. Running multiple long extension cords to different parts of the system, such as one to digital components and another to analog components, would reduce cross-talk of digital noise into analog signals that may occur via the ac power distribution arrangement, similar to what multiple dedicated ac lines might do.
This assumes, of course, that the gauges are adequate to support the current draws and run lengths, which offhand I would think may very well be the case for 12 or 14 gauge, serving typical components.
I'm not saying that it will necessarily be as beneficial in all systems as running dedicated lines from the service panel, just that Elizabeth's observations sound plausible.
Regards,
-- Al