Glossary
Trash
The holding area macOS uses for files you have deleted but not yet erased.
When you delete a file in Finder, it moves to the Trash. It still occupies space. You can put it back. Emptying the Trash is the permanent step, and it is separate. A cleaner that skips the Trash is harder to undo.
Disk Housekeeper sends removals to the Trash by default, after a preview. That applies to Smart Clean and to Autopilot's watched-folder cleanup. If free space did not return, the Trash is the first place to look, before you assume the clean did nothing. The history records what was saved once the space is actually released by emptying it, and you should read both.