A 1920s brand whitened teeth by burning off enamel with acid

Evidence

Some were admittedly even worse: Tartaroff, for example, which claimed to turn teeth “into gems of pearl-like beauty,” in fact whitened them by burning off enamel with hydrochloric acid. — Tim Wu, The Attention Merchants, 289

Categorization

• CANDY: Delightfully absurd historical detail about unregulated early consumer marketing.