Are you talking about removing the flux and what-not, or something else? I think I know what you're saying, and if I'm correct, you don't have to worry about anything. Copper is a perfectly legitimate brewing metal. With brass, some say that you need to "pickle" the brass pieces in peroxide and vinegar to remove excess lead, but I don't believe that applies to copper. A brief soak in vinegar + water would remove any oils or other manufacturing residues. Am I in the ballpark?