from a suggestion on G+ by Joshua Bearden; text from Wikipedia
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, his faeces (and even his sweat, according to legend) would consist of honey. When this diet finally proved fatal, the donor's body would be placed in a stone coffin filled with honey.
After a century or so, the contents would have turned into a sort of confection reputedly capable of healing broken limbs and other ailments. This confection would then be carefully sold in street markets as a hard to find item with a hefty price.