There was a porn version called "Pirates", but porn versions are satire, not mockbusters. And yes, there were a few confused purchases, but it was much higher budget than most mockbuster. I think there actually mockbuster versions of Pirates (cheap porn, posing as expensive porn, which was itself a "satire" of a Disney movie).

Most mockbusters are made by 1-5 young animators, and they do the scripts and voice acting themselves. Pirates was notable for being one of the most expensive pieces of porn ever made (since it a real boat).