It's a childish and unpleasantly cocky tactic that only exacerbates the inside joke framing device of the movie, wherein film producer Wai Cheung (Chapman To) talks to a group of film students about his experiences in the industry, securing funding for low budget, trash projects. To start, he compares himself to pubic hair, noting that his purpose is similarly to reduce friction in sticky situations.
From here, this awkward Hong Kong import covers the gamut of perversion, featuring a business meeting where Wai Cheung eats cow vagina and is forced to fornicate with a mule in order to secure funding for the remake of an old porn film. The clincher is that the financiers want the remake to feature the original actress, who is now in her 60s.
This, aside from a subplot about our producer protagonist trying to borrow money from his ex-wife, is all there is to this film. The broad jokes never hit home and the preoccupation with unprotected mule sex is ultimately the only real trajectory.
It's possible that something is lost in translation, since the English subtitles are routinely incoherent, but this subtext-free exercise in self-congratulation and schoolyard humour has little merit beyond its insinuation that when eaten, cow vagina is referred to as "bliss."
There's also a sidebar about using pop rocks during fellatio to heighten sensation. (China Lion)