Blood would have some amount of saltness that would definately marr a finish but as said, it's most likely used as a fabricated selling point, rather than the drab aforementioned explanation! ^
Eek, toothpaste does it too huh? Interesting. Toothpaste can be actually quite abrasive (well i guess it needs to be, to a point) which would explain why it can also be used as quite a good metal
polish on certain materials. Fresh minty aroma on a mirror finish piece of metal may be appealing to some i suppose
