All these traditional cooling techniques will reduce the temp by a couple of degrees Celsius right? When you're facing 40C can your body even feel the difference?
Absolutely. If you bring the temperature down even a couple of degrees it's a huge relief comparatively.
People are extremely sensitive to temperature changes above 37C/99F for obvious reasons. The higher the ambient vs. core body temp, the more you must sweat and hydrate to not overheat. If it's too humid for sweating to work, it's a miserable way to die.