How to delete Bugzilla saved-searches as administrator?

Users can create and save searches in Preferences // Bugzilla – Saved Searches

Here they can publish them to a group Share With a Group and they will be listed for all users. Over the years the list is filled with useless Saved Searches by inactive users.

How can I delete Bugzilla saved-searches as administrator?

Bugzilla has a "sudo" feature where an administrator can log in as a specific user for troubleshooting. It's disabled by default because it's easy to abuse. If you go in the params and turn that on, you can use it to log in as that user and unshare their queries.