I asked Jorma Kosky from Jorma Design cables that same question. Specifically I asked him if I hadn't used my speaker cables in 6 months, how long would they require reach the same level of break in again? This was his response -
The same principle can be applied to components. You certainly don't go back to square one, but I would think your gear would need 1-2 weeks regularly playing a signal to be refreshed.
When the cables have not been used since then, they need a little time, I can not say how long, it depends on so many factors.
The same principle can be applied to components. You certainly don't go back to square one, but I would think your gear would need 1-2 weeks regularly playing a signal to be refreshed.