You can do this Shabar mantra chanting for 11, 21, 31, or forty one days, the location and time of mantra chanting needs to be the same for the volume of days you wish to do sadhana. You need to use Rudraksha or Tulsi rosary to chant the mantra. https://your-directory.com/listings13203063/a-simple-key-for-most-powerful-sarv-karya-sidh-shabar-mantra-karya-siddhi-shabar-mantra-most-powerful-shabar-mantra-unveiled