In my Origami Art collection, I folded the jewellery with 999 sterling silver sheet. While they are mostly pure silver without any coating on top, so inevitably it'll be oxidized when you wear it for some time.
Here's the method I use to clean the silver jewellery. The materials required are very basic and the result is excellent!
I filmed the video below with my Cantonese voice over. So let me write the steps here in English:
Boiling water, salt and aluminium foil.
Portion of salt and water is 1:5 (or 1:3 also works).
Step 1: Boil water.
Step 2: Add salt and a piece of aluminium foil into the boiling water.
Step 3: Put the oxidized silver item in it until the item is cleaned.
Step 4: Take out the cleaned silver item and rinse it with water. Done!
Please note the water has to be boiling when you clean the silver item. Each time do one item only. If you need to do another piece, better make the new salt water and use new aluminium foil sheet again.
It is really simple and works wonder!