Since they are linked machine gun ammo, even if cleaned you wouldn't want to shoot them due to them usually being loaded hotter than normal to always function in the automatic weapon. That being said their value lies in the configuration you found them in. Since they are linked, I think that you could roll them into a loose ball, and clean in a tumbler, or vibrating brass cleaner with any type of media cleaner. Being linked and lightly rolled, the pointed bullets couldn't come in contact with the primers , so should be safe from contact detenation. Nice find, and hope that works for you.