Messenger of Allah ﷺ said, "If I had not found it hard for my followers or the people, I would have ordered them to clean their teeth with Siwak for every prayer." (Using translation from Bukhārī 887)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ «لَوْلَا أَنْ أَشُقَّ عَلَى النَّاسِ لَأَمَرْتُهُمْ عِنْدَ كُلِّ صَلَاةٍ بِوُضُوءٍ وَمَعَ الْوُضُوءِ بِالسِّوَاكِ»