This thread has veered so far off course that I'm sure it will be impossible to bring it back, but consider this.
Burn-in on wires is, by definition, a process that takes place over time, quite a long time (even with cable cookers and the like).
Substituting one component in a system for another can take 5 minutes or less.
If what we know about auditory memory is correct, how can you ever effectively demonstrate to a non-believer the effect of burn-in?
There's time lapse photography of grass growing and glaciers moving (and melting). But there's no equivalent in the world of sound.
Or is there.....?