Water is used because of its extremely high heat capacity and wide availability: https://en.wikipedia.org/wiki/Table_of_specific_heat_capacities https://en.wiki

Water is used because of its extremely high heat capacity and wide availability: https://en.wikipedia.org/wiki/Table_of_specific_heat_capacities https://en.wikipedia.org/wiki/Table_of_specific_heat_capacit... The concentration of salt has a huge effect on the resistance --- there is an infamous YouTube video of this effect being demonstrated with an electrode boiler.