How can Reusable Blocks be fully deleted?

All of the reusable blocks on one of my sites were deleted last week. Not just deleted, but the trash emptied. I've already had a security vendor audit the site, and they concluded there was no hack, it was done by a legitimate user. No one was using the database directly, so it had to be done in wp-admin.

The only way I can find for reusable blocks to be completely deleted is to visit the page http://example.com/wp-admin/edit.php?post_status=trashpost_type=wp_block. (On that page there are 3 ways to permanently delete: an Empty Trash button, individual Delete links, and a Bulk Actions to delete all that are checked.)

Is there some other way in wp-admin that all the blocks could be completely deleted?