O.K, Ill answer it,
the same reason that ClO2 is used in the pulp paper industry (the biggest use of ClO2 in the world), it's bleaching properties, they use a teeth tray with NaClO2 and phosphoric as the activator and put in the mouth for 3 to 4 minutes daily.
The other way is a ClO2 gel and they use a lazer light to activate the NaClO2
But I quote, the strength is equal to 1 drop of activated Miracle-Mineral-Supplement .
ClO2 strips the enamel by attacking the colligen and getting underneath the enamel!