Silver dollars and half dollars are often collected for more than their silver value, cleaning them will only ruin their collectable value. You will never add value to a coin by cleaning it (the exception being coins dug out of the ground) and can possibly shave tens, hundreds or even thousands of dollars off the value of your coin by cleaning it.
Rubbing it gently with sodium bicarbonate.
Mix salt and vinigear, and soak it in. But if its valubale, DO NOT USE TOO MUCH SALT.
You don't.
http://home.howstuffworks.com/how-to-clean-furnishings3.htm
no
Can you? Yes. Should you? Probably not - you'll remove toning (which many collectors like) and likely scratch the coin's surface.
you use baking powder and coke
Use windex and a coffe filter liner thing to wipe it off and it should be gone...
Silver jewelry can be cleaned with a mild soap and water solution, or with a silver polishing cloth. For tarnished silver, a paste made of baking soda and water can be effective in removing tarnish. It is important to avoid using harsh chemicals or abrasive cleaners, as they can damage the silver.
One suggestion is Lemon or Lemon rinds
It happens with exposure to air and certain chemicals. The silver atoms combine with oxygen to form a layer of silver oxide, which is what causes the discoloration.See the Related Links for "How to clean and polish silver" to the bottom for the answer.
To clean silver jewelry that has turned black, you can either use a silver polishing cloth or a solution of water and mild soap. Gently rub the tarnished areas with the cloth or solution, rinse with water, and dry thoroughly. Avoid using harsh chemicals or abrasive materials as they can damage the jewelry.