Shaikh Abdul-Muhsin al-‘Abbad hafidhuhallah was asked:

Question:

What is the ruling on miswaks flavored with lemon or other than that?

Answer:

It does not affect. As long as it is something entered into the mouth and removed, it does not affect.

[Sharh Sunan Ibn Majah no. 122]

Translated by

Faisal Ibn Abdul Qaadir Ibn Hassan
Abu Sulaymaan