For interconnects, and speaker cables, consider a "professional" accelerated burn in process lasting approximately three days, for about $20 to $30 at cableburner.com
I found that the gadget used by George Saubon produced a positive performance change, even on interconnects that were already well used, and already had been burned in specially by my using a special CD-R from Purist Audio Design.
For power cords, there is an inexpensive plug that allows you to "exercise" your power cord to the max. See archived past discussions about power cord burn-in for more detail on that topic.
I found that the gadget used by George Saubon produced a positive performance change, even on interconnects that were already well used, and already had been burned in specially by my using a special CD-R from Purist Audio Design.
For power cords, there is an inexpensive plug that allows you to "exercise" your power cord to the max. See archived past discussions about power cord burn-in for more detail on that topic.