The final rinse would remove the last of the contaminants
The greatest invention in the history of man is beer. https://youtu.be/2v3QrUvYj-Y Member. SFFP, Shooters Union. SSAA, the powerful gun lobby. Hunt safe.
If you don't let your cases get real dirty then you don't need a tumbler . Washing them in CLR and warm water will get all the patina and grime off . Then rinse twice in quite hot water and dry in Sun or hair dryer or very low oven with the door left open . No heat guns either.