10. Anointing oneself ("sicha") [on Tish'ah B'av] is forbidden only when
it is done for the sake of pleasure ("Ta'anug") (1). However, a person
whose body itches or who needs to anoint himself for other medicinal
reasons, may do so (2).
(1) Any substance, liquid or solid, that is commonly applied to the body,
is included in this prohibition (See Mishna Berura 554:28). Therefore one
may not apply oil, alcohol, hair tonic, cream, ointment, perfume and the
like, if the anointing is being performed purely for pleasure. One may not
anoint even one limb.
(2) This is true even if postponement of the anointing will not result in
danger. The use of deodorant to remove or prevent bad odor is permissible
(See Beur Halacha 554:16). If Tish'ah B'av falls within 30 days after a
wedding, the bride may anoint on Tish'ah B'av so as not to become
unattractive to her new husband ("Shelo tisganeh al ba'alah").