Breath mint

A breath mint was a type of candy primarily consumed to freshen the smell of one's breath. After analysing the foul breath of Trojan, a creature created from the DNA of various alien species, K9 Mark 2 suggested to Thorne that next time he may incorpate some "breath mint DNA". (TV: The Eclipse of the Korven)

Coming to the aid of the Judoon captain Tybo, and smelling his bad breath, Clyde Langer advised "you need a mint, mate." (TV: Prisoner of the Judoon)

When meeting Ashad, the Lone Cyberman, the Thirteenth Doctor noted that the Cyberman might need a breath mint. (TV: The Haunting of Villa Diodati)