I worked in a music shop during high school and pulled apart a few tubas worth at least that. We had a similar magnet tool, but it didn't always work perfectly, and could leave scars in the metal if you weren't careful. His tool might be better, or he might have gotten lucky.
We certainly didn't try to unroll them, however, and I let my mentor solder them back together.
Funny trivia: The article uses ' as delimiter here, as in 10'000 although Germany (the domain name uses .DE and the company is based there) uses the . here -> 10.000 Seems like the author ('from Italy') of that post is using the swiss notation? Any other (european) country using ' as a thousand separator?