One way would be when you a re still on the timeline. You can HARD COMMIT a blank top layer once all our edit is rendered. Then you can choose RENDERING from the tools and unrender and then select your edit.
This will unrender all of the soft effects under.
The intermediates function is for when you have history active... history will then delete all of the things it can rerender and just save the metadata of the effect. Freeing up the intermediate render.
Soft effects also have a COMMIT EFFECT option (timeline)... this will delete the intermediates, but no longer makes the effect soft and editiable so I never use it.