Anandakanda 1.4.478

1.4.478

cūrṇaṃ vā nṛkapālaṃ vā cūrṇaṃ kṛtvā vinikṣipet /
nirudhya ca dhamet tīvram evaṃ kuryāt punaḥ punaḥ //

or having made powder of a human skull, one should introduce the powder; / and having sealed [it], one should blow intensely; one should do this again and again.