LodgeSeasoning Spray (8oz, Yellow)

Any reason why better to spray oil on then rub with a basting brush? I can buy an oil sprayer & use other oil like avocado?

So what is the 5th piece in this set?

Those this stains the cast iron skilet

Has anyone verified this is the “real” thing? Having received fakes/imitations of other items on Amazon I want to be sure...