I thought all modern water-cooled engines (past 40 years) also used antifreeze to increase the boiling point of the coolant. Maybe a heavy-duty search at new car dealers would help. Maybe you will experiment and discover a better solution for crock-pot cleaning of engines.

Maybe the cleaner in the antifreeze is the real ingredient needed and maybe a diluted solution of radiator cleaner and water would serve the same function.

Bill