You'd have to admit the nature of porn is a little different from a 9-5 bank teller job. The nature of their job generally requires a mood. If some are inclined to do ***** recreationally they likely find that mood in recreational ***** or ***** prior to performing or just in general. Not much different from a person who does recreational ***** or ***** in general and engages in it before sex
I could play the Devil's advocate here and say that the difference between what you said above and people using it or ******* to more easily get through a scene or to even manage to get through a scene at all might only be splitting hairs in a lot of instances.
In that case it would even counter some of your first point in that while ***** might not the reason they do porn, porn might be the reason they do *****.
That doesn't even take into account the people that would never have started taking them in the first place if they weren't around so many other people in the industry that do them.