Which products are recommended to clean and polish a cooking pot?
Aluminium rusts white but that looks like stainless steel which if it rusts will rust brown. Not sure what the residue is. Have you tried just simmering water for a while?
Either way, I would just scrub it with soap and steel wool. The scratches might cause you problems if you decide to scramble eggs in it but since it's generally going to be hot when in use and dry when not, it's not going to be a food safety issue.
If you really want to use a product then use something based upon sodium hydroxide and neutralize it with vinegar or something if it feels slimy when you're done.