It was amazing Jan, I just put the wire between the two plastic blocks and whacked it with a hammer. The ear wires came out completely untouched, but firmer. The blocks are even a little textured, and the thought of putting my beautiful wire between them and whacking it was freaking me out, but they didn't flatten or mar in any way. I'm not sure I whacked the wire hard enough, but it seems pretty firm, so I guess it's okay.
I tried to find more detailed instructions on using the Whacker (and how hard to hit it), but couldn't find any on the Internet ...