Perhaps you could pick up some conductive paint? You'd need to cover the bottom and top of the stick, plus a little line connecting the two. You could also try a little piece of copper tape cut into a circle, but you'd still need to connect it to a conductor of some kind on the top that you could touch I think. If you go this route make sure there are not wrinkles or sharp corners that could scratch the pad. Another thought is to buy a pair of those knit stretch gloves that allow you to operate your phone (there are soft conductive strands in the fabric). Cut off a fingertip and glue it to the stick component. Finally, you could apply a little copper or silver(aluminum) leaf -- you can pick it up at Michael's. I've had good luck making 3D prints look metallic that way, and they're conductive. You'd need to smooth the part first before applying the leaf. Go google fishing for specific directions. It's not particularly difficult if you can put up with imperfections in the finish.