A senior Mufti mentioned that the following Durood is extremely effective and powerful for combating sihr and jinn problems,
اللهُمَّ صَلِّ وَسَلَّمْ عَلَى رُوْحِ سَيِّدِنَا مُحَمَّدٍ فِي الْأَرْوَاحِ وَصَلِّ وَسَلَّمْ عَلَى قَلْبِ سَيِّدِنَا مُحَمَّدٍ فِي الْقُلُوْبِ وَصَلِّ وَسَلَّمْ عَلَى جَسَدِ سَيِّدِنَا مُحَمَّدٍ فِي الْأَجْسَادِ وَصَلِّ وَسَلَّمْ عَلَى قَبْرِ سَيِّدِنَا مُحَمَّدٍ فِي الْقُبُوْرِ
O Allah, shower peace and mercy on the soul of Sayyiduna Muhammad صلى الله عليه وسلم amongst the souls. And shower peace and mercy on the heart of Muhammad صلى الله عليه وسلم from all hearts. And shower peace and mercy on the body of Rasulullah صلى الله عليه وسلم among bodies. And shower peace and mercy on the grave of Rasulullah صلى الله عليه وسلم amongst all graves.