Demagnatizing Phono Cartridges

Many cartridge manufacturer's say DON'T use an electronic cartridge demagnetizer. Having purchased a Koetsu RSP through our Tokyo office, I got an email to Mr. Shugano. He is strongly against them. Of course, there is some degradation of the permanent magnet when you use an electronic demagnetizer. There is just a great deal of disagreement as to how much the degradation is. I only use the Cardas Sweep Disc now.

I have an interesting question. If the coil wire is, say, copper, how does it get magnetized? Same with silver. I thought these metals to be non-magnetic.

I have owned several Lyra cartridges, including my present favourite the Helikon. Scan Tech recommends frequent Demag for best performance. Presumably, it remains a matter of opinion.