Anyone have experience with "burn-in generators"?

It seems to me that the biggest problem with Cable Cookers is their manufacturers' claims that they can completely break in a brand new cable in 2-4 days. Imagine you have a new interconnect or speaker cable, which normally requires 250 hours of music signal to burn in. If it spends the first 4 days of its life on a cable cooker before installation in your system, my repeated experience (across a variety of cable types) is that it's still going to require 250 hours of music signal! All that cable cooking achieves is to make the cable sound less bad while you're getting the hours up.

Phono cables are a different issue, while several respondents also refer to using a Cooker to "refresh" well-used cables; I don't dispute any of those observations.

I've had and used the Hagerman Frykleaner Pro for several years, and have had no reason to be displeased with its performance regarding the run in of various cables. The Cable Company burns in its cables, though I haven't asked about which particular device they use. Of course, their cables are moved about/rolled up and sent through the mail to those wanting to audition them. In those instances when I have received any of their cables I've typically given them a short "refresh" or restorative(?) burn in with my Frykleaner Pro before listening.

After having my Audiodharma Cable Cooker (from Audio Excellence AZ) for two years, I think they are required equipment for any audiophile who wants to enjoy the full potential of their power cords, interconnects, speaker cables and even headphone cables.
It has greatly improved my Audioquest, Black Sands, PS Audio, Morrow, and Synergistic Research products. And yes, a short refresh on the Conditioner every three to four months is worth the effort in sonic improvement.

I just realized that the LHC (the large particle accelerator built in Switzerland that recently found the Higgs Boson and contains billions of dollars worth of unbelievably sensitive detectors) probably did not burn in their cables! Shall we let them know that burning them in will definitely improve detection?

the problem with break-in devices is that they provide a signal different from a music. thus the sound of the cable will differ after it is "burned-in", with one of them vs passing a musical signal.

also consider the current requirement of the component receiving the cable. burning in a cable with a low current source for a component that has a high current use, e.g., an amp, will create a different result than providing a signal from a high current source.

thus, i have been told to connect a power cord to a refridgerator to burn it in for use with an amp.