My answer was partly a joke, though it was entirely accurate. On Tishah B’av, however, perfume is Assur, most hold mouthwash is Assur, and deodorant is a Machlokes. On Yom Kippur all three are Assur.
Perfume is prohibited for men to use all year as it is considered a women’s “garment”. Deodorant and tooth brushing maybe permitted because Kovod Ha Breas even on a fast day. It all depends how often one bathes and brushes their teeth.