You can do this Shabar mantra chanting for eleven, 21, 31, or 41 days, the spot and time of mantra chanting needs to be the same for the amount of days you want to do sadhana. You need to use Rudraksha or Tulsi rosary to chant the mantra. It https://http-directory.com/listings13049455/most-powerful-sarv-karya-sidh-shabar-mantra-karya-siddhi-shabar-mantra-most-powerful-shabar-mantra-secrets