I think you are well beyond cleaning that thing... money will be whatever scrap is worth on 1/10th of a gram of copper or whatever might be left on it.....
To clean it pour some Coca cola in a glass and leave it overnight it will be so clean you won't even see it in the morning.LOL I have rolled some like that and told the bank they were dirty coins and they said no problem they would just send them in as mutilated.