Begin this mantra during a waxing phase of the Moon. The ideal time of day to chant a planetary mantra is in the early morning, when all is quiet. Mantras can be started at any time, however it is best not to start within three days on either side of the dark Moon (New Moon). If possible, start when the Moon is bright and waxing.
How to Chant the Ketu Mantra
Chant the Ketu mantra 17,000 times. This need not be done in all one sitting. See the Planetary Mantras page for how prayer beads help with counting, and for more tips.
Pronunciation
Palasha-pushpa-sankasham taraka-grahu masta-kam rowdram row-drat makam goram tam keytoom prana-mam mya-ham
I offer my obeisances to the violent and fearsome Ketu, who is endowed with the potency of Lord Shiva. Resembling in his complexion the flower of a palasa plant, he serves as the head of the stars and planets.
English translation
Why it Works
The Ketu mantra can be seen as a type of prayer that invokes the grace of a planetary energy to lessen its negative effects as revealed in the horoscope.
There are many kinds of astrological mantras. Some are devotional, some are Vedic, and some are Tantric. The mantras given here are mainly devotional. Therefore, while one should be careful to try and pronounce the mantras as accurately as possible, they will still work with individual pronunciations.
For more on how planetary mantras work, see the Planetary Mantras page.