Have any of you tried the metal detector Otto Frei sells? I see it's sold by other sites as a treasure-hunting device, so I wondered if anyone here has tried it on actual watch parts. A while back I had to hunt for a stainless steel screw, so my usual magnet didn't work. I found it, but it was frustrating. This device says it works on non-ferrous materials too. But can it really detect something so small? It seems too good to be true.