Anandakanda 1.4.349

1.4.349

mūtrāmlairvipacenmandaṃ vahnāveṣa biḍo mahān /
<11. vajrānalabiḍaḥ>
arkakṣīrairdagdhaśaṅkhaṃ śatadhā bhāvayettataḥ //

one should cook [them] gently over fire with urines and sours; this is the Mahābiḍa.
<11. Vajrānalabiḍa>
Then one should steep burnt conch shell a hundred times with calotropis milk;