Jaydog, best advise I could give you from my own experience is....Don't clean any coin until you find out the value. If your talking about clad dug up from detecting that is dirty, many of us just use a tumbler with some soap and aquarium gravel. That will clean off the dirt and bring some of the shine back so you can turn it in.
Now if you talking about a coin that might have some value either from detecting, someone left them to you or you bought, don't touch it with any thing but gloves on. There are coins out there that have conciderable value in even the worst grade. By cleaning a coin you will reduce the value sometimes by 50% or more.
Believe me, many of us just getting into collecting have done just this. Gotten an old coin that looks dirty and thought the value would be more if it was nice and shiny. Only to find out the coin was worth way more untouch then cleaned.