Deleting individual sounds from Sound Library?

Let's say I have downloaded a specific sound "Piano → Processed → Dusk". This is one of the many sounds that I've tried and realized I will never use. How do I remove specifically this sound?

As is clear in the image below, the "Delete" button is no use here. It seems to be always disabled / grayed-out no matter where I click. It actually makes me wonder if it's ever clickable.

An answer to a past thread suggests that individual sounds can be deleted by tampering directly with the file system. However, I can neither find the relevant file by searching for "Dusk" under `/library/Application Support/Logic`, nor can I somehow logically locate the file based on the content locations resource.

I would really appreciate a definitive answer to the question: is it possible to delete an individual sound? If yes, how? If no, why not?