Your talking about saving pennies by doing that and after the fact you drain your tank down and then fill it up and the water heats back up in it, how much money do you really think you’ll be saving?
Hot water tanks are basically disposable items. You get anywhere from 10-15 years out of them and you replace them. If you’ve gotta tank with a thermocouple, you may want to change that every other year as a preventive maintenance but even then you’d want to consider replacing the tank because they stopped putting thermocouples in years ago.