On 20 Jan 2021, there was a thread on QRP-L about what to use for cleaning CW keys. Several remembered using Brasso, but the winner seemed to be NEVR-DULL, available at Ace Hardware, Pep Boys, True Value and Wal*Mart. One tin should last many years. It's a good thing I moved out of California after living there for fifty years, as that's the only state where you can't buy it.  CA doesn't allow switchblades either. I think I'll take my chances and try out the magic in a tin.