It could be it. When I saw the trailer that time, there was a scene with Joanna Angel, sucking cock and saying something with "Daddy" to the guy. There wasn't that part in this trailer, but I'll check the whole documentary and see. It's available to see on:
The same file can also be downloaded from here:
Yesterday I downloaded and saw a documentary with a similar name - "Porn - Business of Pleasure", and she was in that as well, though as a person being interviewed, not as someone to frighten people up regarding the wrong kind of porn...
That one and some other porn/sex documentaries can be downloaded from here: