You can do this Shabar mantra chanting for 11, 21, 31, or 41 times, the place and time of mantra chanting needs to be exactly the same for the quantity of times you want to do sadhana. You can use Rudraksha or Tulsi rosary to chant the mantra. It https://webtechdirectory.com/listings13055065/indicators-on-most-powerful-sarv-karya-sidh-shabar-mantra-karya-siddhi-shabar-mantra-most-powerful-shabar-mantra-you-should-know