In a fantasy world, I would consider it if I got to chose the porn actress and how it was filmed. I might consider a Point-Of--View POV style movie where the camera is mounted on my head, so you'd have a great view of the woman taking care of my cock, but never see my face. It would also not have any dialog from me, so my voice couldn't be traced back to me in any way.
If a stationary camera system was being used, I'd only do it wearing a mask over my head, like those Mexican wrestlers use.
In the real world? Nope, never going to happen.