Our magical fix has been alcohol on stainless fittings. Almost any
stainless fitting that freezes can be loosened with common alcohol. It
is better than Lockease or Liquid Wrench (I keep both of these on board
as well).

Nancy’s favorite passtime is polishing brass (well, maybe not favorite).
She uses lemon juice and salt on bad spots and a tooth brush where a rag
can’t reach.

We use lemon juice or Reallemon to help clean up aluminum (like the
window trim).

In both cases, clean well with soap and water and wax afterwards. There
is no protection at all once the lemon juice attacks the oxidation.