Narrated Zayd ibn Khalid al-Juhani:I heard the Messenger of Allah (saws ) say: Were it not hard on my ummah, I would order them to use the tooth-stick at the time of every prayer.
Abu Salamah said: Zayd ibn Khalid (ra) used to attend the prayers in the mosque with his tooth-stick on his ear where a clerk carries a pen, and whenever he got up for prayer he used it.
Sunan Abi Dawud 47
“The Prophet of Allah (saws ) would clean his teeth with the Siwak, then he would give me the Siwak in order to wash it. So I (Aisha ) would first use it myself, then wash it and return it.
Sunan Abi Dawud 52
Narrated Aisha, Ummul Mu’minin:
The Messenger of Allah (saws ) said: Ten are the acts according to fitrah (nature): clipping the moustache, letting the beard grow, using the tooth-stick, cleansing the nose (Al-Istinshaq) with water, cutting the nails, washing the finger joints, plucking the hair under the arm-pits, shaving the pubes, and cleansing one’s private parts (after easing or urinating) with water. The narrator said: I have forgotten the tenth, but it may have been rinsing the mouth.
Sunan Abi Dawud 53
In-book : Book 1, Hadith 53