I sell jeewelry for a living, a silver dip or polish can be damaging to your gem stones. This is going to sound crazy but it works.
Get a small glass bowl, line it with aluminum foil, shiney side up
Put your silver jewelry on the tin foil
Cover your silver jewelry with baking soda
Pour boling hot water over it until it is completley covered
Do it in a sink, the reaction causes fizzing and it may fizz over the edge of the bowl
To polish an old silver dish you should buy a good silver polish and rub it with a non-abrasive material. Silver can de delicatie so be careful!
swiss chalet
Store silver with a piece of white chalk. It absorbs some of the sulphurs from the air that vause the tarnishing. You can also buy anti tarnish paper or bags.
Bite it, put a lighter under it, silver will tarnish in air, fake will not! The best way is to buy a silver testing kit available from a jewelry shop or take it to the shop for testing.
Any precious metal buyer would be quite happy to buy these items from you & no, they wouldn't have to be tarnish free.
you can buy metal polish.
You can buy one from the Grand Exchange or you can buy an Addy Square shield from the shield shop in Falador
Buy a can of spray lacquer and paint it.
buy a shield generator or 2. regards
Obsidian shield
Either buy one or take shield left half and shield right half to make a full shield.
you can just buy nail polish.... and then empty it out...... or if you need empty nail polish bottles right away or something.... then i dont know