It works particularly well on the toilet because it’s slightly abrasive but not gritty enough to damage the porcelain, and it contains oxalic acid, which breaks down rust and mineral stains.

The acid demineralizes the tooth enamel, which then allows the dark pigments from wine to penetrate into the tooth, causing the staining." Dr. Miles Madison soaked four teeth in popular beverages.

A team of researchers at the University of California, Los Angeles (UCLA) has introduced a virtual Gram staining technique that could transform how microbiologists stain and classify bacteria.