Shiva Purana
आदिवारे पंचगव्यैरभिषेको विशिष्यते । गोमयं गोजलं क्षीरं दध्याज्यं पंचगव्यकम् १११ ।
The ceremonial ablution of the phallic emblem with Pañcagavya on Sundays is specially recommended. Pañcagavya is the compound of cow’s urine, dung, milk, curd and ghee.
english translation
AdivAre paMcagavyairabhiSeko viziSyate । gomayaM gojalaM kSIraM dadhyAjyaM paMcagavyakam 111 ।
hk transliteration by Sanscript