How to find AirPods in the case?

The only time I really need to use Find my IPhone app to find the AirPods is when they are IN the case- but this article indicates that when they ar in the case is exactly when they cannot be det dated- they show up as a grey dot at their last location. So, the only option to detect them again is if the case is opened and they are paired with a new device..this assumes that somebody finds them and attempts to use them, without resetting them to factory settings (hold down ton he white button). Am I interpreting this correctly?