The Compendium of Caraka 8.4.38

8.4.38

abhukte śūnyapāyau vā vegāt sneho 'atipīḍitaḥ/
dhāvatyūrdhvaṃ tataḥ kaṇṭhādūrdhvebhyaḥ khebhya etyapi//

[Administered] on an empty stomach or when the rectum is empty, the fat, pressed out with force,
rushes upward, and then from the throat it even comes out through the upper orifices.