Rasendracudamani 14.54

14.54

tatastrikaṭukakvāthe tridinaṃ sthāpayettataḥ /
utkvāthya bhasmanā mṛjya jalaiḥ prakṣālya sāraghaiḥ //

Then, one should place it in a decoction of trikaṭu for three days.
Boiling it, scouring it with ash, washing it with waters, [and] smearing it with honey