I was originally trained as an Industrial chemist... analysed vinegar at one stage
Whats happening here is that vinegar is between 5-15% acetic acid a mild organic acid compare to mineral acids like hydrochrloric, phopshoric etc.
What you are doing are gently etching those parts. Which is fine and works well on sensitive items. For rugged items you could upgrade a little, coke is stronger, I think it is similar strengh acid but is phosphoric, ouch.
Your bleach is peroxide which I think will have indetermiate results. If you have organic residues it might lift them off. Be careful on aluminium as it forms an oxide layer that seals it. You might try caustic and buffing.
A milder approach on steel is the reverse, that is use caustic soda a strong base (NaOH), be careful though as both strong acids and bases burn you.
NaOH by nature does not etch which is a good thing as once metal is etched off you cant put it back
