"What would the Messenger of Allah ﷺ do as soon as he entered the house?" She replied: "(He would use) the siwak." (Using translation from Abū Dāʾūd 51)  

قُلْتُ لِعَائِشَةَ بِأَيِّ شَيْءٍ كَانَ يَبْدَأُ النَّبِيُّ ﷺ إِذَا دَخَلَ بَيْتَهُ؟ قَالَتْ بِالسِّوَاكِ