The Best Gasket head gaskets work well installing them dry.  There is a form of sealer built into them so nothing extra is required.  While doing the cylinder head tests on the dyno mule, it was found that spraying them with WD40 allowed the gaskets to be removed without tearing.  I’ve reused the same ‘Best Gasket’ head gaskets on as many as four head swaps doing this without any gasket sealing issues.  While spraying them with Copper Coat probably wouln't be detrimental, I don't think there's anything to be gained by doing it.