Reference: Salīm, ʿAmr ʿAbul-Muniʿim (2006), al-Masāʾil al-ʿIlmiyyah wa al-Fatāwā al-Sharʿiyyah Fatāwā al-Shaykh al-ʿAllāmah Muḥammad Nāṣir al-Dīn al-Albānī fī al-Madīnah wa al-Imārāt, First Edition. Ṭanṭā: Dār al-Ḍiyāʾ.
Question: “What is the ruling of using the siwāk and with which hand should we use the it?”
Response: “The siwāk is a Sunnah encouraged by the Prophet in many aḥādīth.
As for which hand the siwāk should be used; we have no text specifying that.
Some of the scholars say with the right and others say with the left and both views have a point.
Those who say with the right take it [from the fact that the Prophet would] begin from the right in all things.
Those who say with the left argue that it is a form of cleaning and they connect it to the cleaning done after answering the call of nature etc.
That is why this matter is left to every person according to what he finds peace with.” [p. 77]