Derusting of electrical installations
With blasting dry ice one can remove 'fly' rust only because dry ice is soft and does not damage nor scratch the substrate.
If you want a shiny or rough finish you need to remove the toplayer with an abrasive hard medium that is harder than the substrate. The "Dry Ice & Grit Blaster" allows to add a little bit abrasive 'sand' to the dry ice and gives that shiny & rough result.