Kautilya's Arthashastra 14.3.4

14.3.4

trirātropoṣitaḥ puṣyeṇa śastrahatasya śūlaprotasya vā puṃsaḥ śiraḥkapāle mṛttikāyāṃ yavān āvāsyāvikṣīreṇa secayet //

Having fasted for three nights, one should, on the day of the star, Pushya, catch hold of the skull of a man who has been killed with a weapon or put to the gallows. Having filled the skull with soil and barley seeds, one should irrigate them with the milk of goats and sheep. Putting on the garland formed of the sprouts of the above barley crop, one can walk invisible to others.