I purchased a rock tumbler and 1lb of stainless steel tumbling media I can re-use. I wait until I have enough coins then I tumble them for a few hours to clean them up. This is great to prepare them for turn in as the machine at my bank accepts 99% of my tumbled coins.
Don't mix pennies / copper and other coins as the copper will stain the others. And do not tumble and high content silver or other valuable coins. It's only for coins I intend to turn in.
I I find an old wheat penny or other non-clad type of coin I prefer electrolysis to tumbling to clean them, and carefully consider the numismatic value of a coin before cleaning it in any way.