Actually, back in the day, Hollywood made things look really clean, especially sci-fi...it was only after Star Wars and a few other things (Blade runner, etc) that 'dirty' became 'respectable'..;)
There's oodles of dirty textures out there you can apply to models, RDNA, Devian Art, etc., though some of the conditions are a bit onerous...;)

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)