Double-click the Cache component for its default Niagara Virtual Cache View.

As shown, this tabular view lists cached virtual ords, with a station select dropdown list at the top. Click row(s) to select, where bottom buttons let you Select All, or Remove any selected.
Double-click a row for a popup window showing details on data in the virtual cache.

The cached data includes a target’s slot ord along with information on its facets and slot flags.
In the case where a recent facets or slot flag change has been made to the target of a virtual component, but is not properly reflected in Px access of it, you can check it here. If necessary, you can then remove it from the virtual cache, so it can properly update and be added back in the cache upon next access.
The Select All is available too, which can be used NiagaraStation-wide to remove all cached data. In addition, note the Cache component has a right-click Clear action, accessible on the NiagaraNetwork property sheet.
Clear removes cached data for virtual components across all NiagaraStations in the NiagaraNetwork.