I just received some lead & a TON of pre made 2 oz round sinkers. These things have been stored a while. Is there any way to clean them? They have film on them and dust/dirt, etc... I thought they might be able to be soaked in a bucket of water w/ some sort of chemical. When your melting the lead I know that official NRA Beeswax will make the dirt & grime rise to the service.