Question about nonspaced content

I have read the documentation with regards to the nonspaced folder in the Confluence attachments directory. I have begun utilizing that information to remove large content that has been in ‘DRAFT’ status for several years by making myself the owner and discarding it though the UI. This has worked very well, until now.

I have found some folders that do not have a corresponding entries in the content table. I was wondering, since I cannot assign the content to myself and delete it through the UI, if it is safe to simply delete them from the folder tree.

NOTE: The content in these folders is several Gb, so I doubt it is Confluence internals.