Rasarnava 6.60

6.60

jīrṇavastre vinikṣipya madhusarpiryutaṃ puṭet
saṃsthāpya māsaparyyantaṃ tatra śuddhirbhavetpriye //

Placing it in an old cloth with honey and ghee, one should subject it to a calcination fire;
leaving it for a month, purification occurs therein, O beloved.