You are able to do this Shabar mantra chanting for eleven, 21, 31, or 41 times, the place and time of mantra chanting really should be a similar for the volume of days you need to do sadhana. You should use Rudraksha or Tulsi rosary to chant the mantra. https://vashikaran18405.livebloggs.com/38681044/most-powerful-sarv-karya-sidh-shabar-mantra-karya-siddhi-shabar-mantra-most-powerful-shabar-mantra-no-further-a-mystery