To keep Ketu strong, Vedic astrology recommends chanting the Ketu Mantra: Om stram streem straus: ketve namah. It is believed that repeating this mantra 108 times daily helps to pacify the Ketu dosha. Offering blankets, warm clothes, and umbrellas to the needy is also beneficial. Pujas to Lord Shiva are also recommended to strengthen Ketu. Iron, black cloth, and black sesame seeds should be donated to keep Ketu happy.