10bhl 554:15 explains that there is a distinction between Yom Kippur and Tisha Be-Av regarding the prohibition of anointing oneself. On Yom Kippur, the prohibition also includes non-pleasurable anointing, as the Yerushalmi indicates. Therefore, one may not apply a salve for the purpose of removing filth on Yom Kippur. On Tisha Be-Av, however, the prohibition is a function of the laws of mourning. Therefore, only anointing for the sake of pleasure is prohibited, while anointing in order to remove filth is permissible. bhl thus rejects the opinion of Mateh Yehuda, which equates Tisha Be-Av and Yom Kippur in regard to this prohibition.

11Shiyarei Knesset Ha-gedola §§551, 567 states that one may not smoke on fast days, because smoking alleviates the anxiety of the destruction of the Temple and generates a feeling of satiation; it even causes a desecration of God’s name, since non-Jews refrain from smoking on their fast days. According to many other poskim, however, there is no prohibition against smoking, from the perspective of the fast day, especially for one who needs to smoke to relieve agitation. 555:8 permits smoking after midday, in private, for one who needs it. Many others permit smoking even before midday, in private, for one who needs it. These poskim are cited in Yabi’a Omer 1:33. Hilkhot Ĥag Be-ĥag ch. 7 n. 87 states that those who prohibit smoking are not referring to cigarettes, but to a type of smoking that entails more pleasure and involvement. It is by now clear that smoking is detrimental to one’s health, and it is a mitzva for one who is accustomed to smoking to make every effort to quit. Nevertheless, if one is already addicted to smoking, one may smoke on a fast day in order to relieve the pain of fasting.