One possible example could be a pulp fiction that has a lot of grotesque body horror elements. For instance, stories that describe mutations in a very graphic and unappealing way, with lots of gooey and unnatural details. Another example might be a pulp fiction that has offensive and vulgar themes throughout, like a story that is overly misogynistic in a really blatant and crude way which could be considered 'gross' in terms of its content.
It's hard to give exact examples as the term 'gross pulp fiction' isn't a commonly known and defined category. However, imagine a pulp fiction where the author goes overboard with descriptions of decay and putrefaction. Say, a story set in a post - apocalyptic world where the descriptions of rotting corpses and the stench are so vivid and extreme that it makes the reader feel a sense of disgust. Or a pulp fiction that has a lot of inappropriate and lewd content that is not just sexual but presented in a really distasteful and unrefined way.