As the award-winning filmmaker Katy Chevigny says, “The only film you can make for cheap and not have to worry about rights clearance is about your grandma, yourself or your dog.” See Guy Dixon’s article on it here which refers to a report on the pernicious effects of limited copyright for documentary filmmakers.
On an another note, I have two video projects up in the air right now, both of which confront the clearance problem head on; the first project is a documentary about my father’s family and how they grew up in New York in the 1940’s. The second is about ME AND ONLY ME!. While not explicitly about corporate ownership of cultural icons, the second project tries to turn away from cultural references and fold the film into my ego. (“Self-indulgent,” etc.).