Although it is not yet fully understood scientifically, the phenomenon of cable break-in has been experienced by many audiophiles
....
One can now correlate the impressive signal level produced by the CABLE COOKER and the benefits derived by its use with the cabling in our audio/video systems.
Wow that was impressive! The stuff in the middle is simple V=IR math. If is works at low current, why not cook quicker? Why not crank the current up to 10 amp or so? You should really be able cook quickly. And since signals flow only one direction, why not use DC? What is the point of the AC signal?
Yep, dielectrics are not understood at all...
http://en.wikipedia.org/wiki/DielectricIEEE paper where dielectrics are studied to only effect signals at RF and above.