Shaykh al-Islam Syed Husain Ahmad Madani Ra advice was to to recite Durood e Tunjina 70 times daily, for the protection of calamities.
Moulana Ashraf Ali Thanwi RA writes "Durood e Tunjina should be recited a thousand times at the time of any hardship or calamity." (Zaadus Sa’eed, by Hakeem ul Ummah Moulana Ashraf Ali Thanwi, Page 14)
It is realted in Manahij al-Hasanat from Ibn Fakihanis Al-Fajr al -Munir:
"There was a pious saint called Musa Darr (may Allah have mercy on him). He related his own experience to me. He said, 'I was traveling on a boat which began to sink. Suddenly, I was overcome by slumber(sleep) and in this state, I saw the Messenger of Allah ﷺ. He taught me this invocation of blessings and then instructed that all aboard the boat should invoke it one thousand times. We had briefly recited it three hundred times that the boat was saved from sinking.
Fazail -e- Durood p 137
About & benefits
Translation & Transliteration