This process differed from a simple body donation because of the aspect of self-sacrifice; the mellification process would ideally start before death. The donor would stop eating any food other than honey, going as far as to bathe in the substance. Shortly, the donor's feces and even sweat would consist of honey. When this diet finally proved fatal, the donor's body would be placed in a stone coffin filled with honey.[

https://en.wikipedia.org/wiki/Mellified_man