Root cleaning means removing old medium from the roots so you can inspect the plant and reset its growing conditions. It can be useful when the old medium is compacted, too wet, or unknown.
Work gently. Remove dead or unhealthy roots, let wounds dry when needed, and repot into a medium that suits your climate and watering habits.
Do not treat root cleaning as a routine chore for every plant at every moment. Use it when the plant, season, and potting condition make it worthwhile.