It is indeed more powerful against the Shayṭān than iron.
Shaykh Muḥammad ibn ʿUmar Bazmūl
Shaykh al-Albānī said:
He (ṣallallāhu ʿalayhi wa-sallam) would spread his left palm upon his left knee and clench all of the fingers of his right hand, point with the finger adjacent to the thumb towards the qiblah and cast his vision towards it. When he pointed his finger, he would put his thumb upon his middle finger and sometimes he would make a circle with them. When he raised his finger he would move it, supplicating with it, and he would say:
“It is indeed more powerful against the Shayṭān...