Is corrosion inhibitor paste conductive?
The paste inside the AlumiConn does not negatively affect the electrical connection. When the screw is tightened the paste between wire and the metal screw and the metal body of the AlumiConn is squeezed out.

You can use these for copper wires, but it is really unnecessary. In the upper picture the end of the wire is stripped too long. The insulation on the wire is supposed to be inside the skirt of the insulation on the AlumiConn. I think there is a strip gauge on back of the Alumiconn.

EDIT Memory failure! Just looked at my stash of AlumiConns and there's no strip gauge on the insulation.