Breaking in cables with FM static

The white noise from FM occurring between stations with the muting off contains wide spectrum information that could be used as you suggest.

Reproducing this sound through the amp and speakers is not necessary unless they are the intended components for break in. There is no risk to any equipment other than the amp and speaker. Even then requiring uncomfortably high sound pressure levels.

Many break in discs, such as the one manufactured by Purist Audio contains a variety of tones and noises that accomplish the same results in a more efficient manner.

In any case, it's best to mix music sources in addition to the noise to get the best results.

I had not thought of that Bob, that would work just as well while maintaining peace and quite in the living space.