What solution to clean silver and gold contacts?


Hello!

          I am looking for a product to use to clean contacts in my audio system. Contacts are mostly gold plated, but some of them are pure silver on pure silver.
         I do not want anything that leaves any kind of residue / contact enhancement product. I read on forums that some members claim these products improve the sound at first, but later degrade it. So in the end, they removed all of the contact enhancement product from the actual contact.
         Right now I am mostly leaning towards using pure ethanol alcohol, as I think all of it would evaporate.
         Thanks in advance for all of your advices.
audiobb
BTW: Silver WILL form an oxide layer, as long as the, "ambient conditions" are below 195 degrees Celsius(almost twice boiling), and - the atmosphere contains Oxygen: https://study.com/academy/lesson/silver-oxide-formula-decomposition-formation.html
I should have said silver metal does not readily form an oxide layer in air at room temperature. There is some oxidation but it is slight in comparison to sulfide formation.
Perchloroethylene also called tetrachloroethylene is very effective at removing hydrocarbons but not silver sulfide or metal oxides. Also it is a known carcinogen so care should be taken when using it. Although not as effective, ethanol is safer.
@ljgerens 

A question for you, please. I remove silver tarnish by putting the silver in electrical contact with aluminum foil, and immerse both in a hot solution of baking soda. The sulphate ion bonds to the aluminum, leaving the silver intact without pitting. Have I missed something?

Also, I understand that sulphates can be present on the fingers. Is this not correct?

Thanks!