Dom Wynter actually has an afro hairstyle, but had to wear an afro-wig so it would match the hair on the severed head later in the film. This technique was used in Stuart Gordon's Re-Animator and Brian Yuzna's Bride of Re-Animator, where actor David Gale had to wear a somewhat more obvious hair piece for the exact same reason.
The opening shot of exploding guts hitting and sliding down the cellar wall was actually shot nearly a year before principal photography, during the production of a teaser trailer to raise interest and test out lighting effects. It is the only shot from the trailer that remains in the finished film.
Washing up liquid and red coloring was used for blood in most scenes, as it was cheap and looked good enough when being chucked around. For shots where the blood was more prominent, maple syrup and food coloring was used, including the shot where Norbert gets a plasma facial after Afro-Zombie is decapitated.