It is possible and entirely plausible. However i would contest the depth of the scratch as claimed by the person in the video. I would call it a surface scratch in that it is contained only in the clear coat which is the top/surface coat. If it was a deep scratch it would be in the paint layer and thus be harder to repair by this method.
For the scratch shown, plausible and effective way to keep the paint original but free of horrible scratches.