A little trick I picked up off the Viva forum.....a weak solution of citric acid does a wonderful job of cleaning dirty copper electrical parts. I used it to clean a 12S socket on our caravan which had gone green and furry. Home brew shops, good supermarkets and chemists sell citric acid in powder or crystal form. I used a teaspoon to 1/4 pint water - which was quite a strong mix.
You need to thoroughly rinse and dry afterwards, and apply some WD40 to the clean surfaces.
You need to thoroughly rinse and dry afterwards, and apply some WD40 to the clean surfaces.