The process of embalming seems to have varied.
To begin with, he was the god of the dead, of the cemetery, of all supplies for the dead, and therefore of embalming when that became customary.
Embalming seems not to have been universal, and bodies were often simply hidden in caves or buried.
The Ancient Egyptians used thyme for embalming their dead.
Outside Egypt mummification was practised amongst the ancient Peruvians, who took advantage of the desiccating atmosphere and salt soil of their caves for preserving the dead in good condition without any embalming process.