Aluminium will have the opposite effect from what you wish to achieve, the steel will preferentially corrode and protect the aluminium from tarnishing.
Hello, I think you mean zinc. This is also use as anodes welded on
ships to prevent corrosion of the steel hull. Aluminium has the
problem to have a to closed oxide layer. So if you add some pieces of
zinc in the steel shot it would help if some galvanising effect
occurs, if some material which has a higher electrical potential than
steel. And all our precious metals are higher in potential. How ever
the electrochemical protection will only have effect if the fluid is
guiding electrons. This can be done by adding accid or a salt. It is
never wrong to add some zinc I your steel shot. But adding salt for
guiding, I do not know if this is wise. The cure maybe worse than the
sickness. Martin Niemeijer