I can tell you after 10 years, it is totally unnecessary to use anything other than the distilled water. The steam is an excellent cleaner and disinfectant without anything else (it even cleans dried kibble, icing and cookie dough off the wood floor.) Heating any of the above substances to steam creates volatile chemicals in the air and on the surfaces. By the way, white vinegar is not recommended by either the guys who installed and finished out wood floors or by the manufacturer of our sold vinyl plank flooring.
So, I save a fortune on cleaning products and keep the air cleaner too. Even when I spot clean with a cloth, I use just water as much as possible. Maybe sometimes a drop of soap if I have spilled grease.
Sue