Crest White Strips? Why not try Prince's Cherry Paste. Apparently, Regency era people wanted white teeth, too. According to an advertisement in La Belle Assemblee, besides cleansing and preserving teeth, Prince's Cherry Paste whitened them (47). I guess no matter the era or diet, a person had difficulties keeping teeth nice and bright and white.
Cite: Prince's Cherry Paste. Advertisement. La Belle Assemblee 3 June 1807: 47 [Bell's Monthly Compendium of Advertisements for July, 1807 Section]. Google Book Edition.