You are able to do this Shabar mantra chanting for 11, 21, 31, or forty one times, the area and time of mantra chanting should be a similar for the volume of days you should do sadhana. You can utilize Rudraksha or Tulsi rosary to chant the mantra. It https://thedirectoryblog.com/listings13056318/the-greatest-guide-to-most-powerful-sarv-karya-sidh-shabar-mantra-karya-siddhi-shabar-mantra-most-powerful-shabar-mantra