You shouldn't. Cleaning old coins diminishes their value.
No. You might spoil them. Leave that for an expert.
How does vinegar clean coins?
Do not attempt to clean old coins. Anything you have at home will damage the coins' surface and significantly reduce its value!
No, cause then they look older
Don't clean your coins. That will ruin them.
Is it okay to steam clean vintage gold coins
Never clean old coins, pennies, nickels, dimes, etc... Coin collectors want the natural patina. If the pennies have dirt on them then soak them in water to remove the dirt. But don't use any detergents. Detergents can damage the surface of the coin and leave pitting lowering the value of the coin. Also do not rub the coins together to loosen the dirt, this can scratch and wear the coins and lower the value. Coins (US Coins) will be worth face value to a non-coin collector, but if you plan to collect coins or just clean them to sell as collector pieces, then don't clean them.
The first rule of coin collecting is "NEVER CLEAN A COIN" because if the coins have any collectible value, cleaning them kills it. I have seen many coins that have been reduced to face value from cleaning. Please show them to a collector or dealer BEFORE you clean them. You may be very glad you did.
No. Coins always lose value when they are cleaned when compared to uncleaned coins (the exception being coins that are dug out of the ground that are encrusted in dirt). Do not clean your collectable coins!
No, you do not clean coins. Cleaning coins will only damage their value. If you feel you must clean a coin, take it to a coin dealer and see what he recommends to clean the coin, however, they will recommend you not to clean it. Coins potentially worth hundreds of dollars have been brought down to selling them for scrap because people have cleaned them! Do not clean coins!
If anything, bleach will discolor coins. Don't do it.