What does "Day 5 since want day" mean?

Do they count washed days as days the hair gets wet and like you use water to wash out any big grime and yuck or actually washing it with products?

And does the "day X since i washed my hair" mean with products, conditioner, shampoo, ect. And implies that they washed with just water. Or days since they've done anything relating to washing hair, not even water to get some gunk out.

Someone explain please 🙏