The #showoff forum is getting a lot commercial spam aimed at a general resident audience even though this channel is only accessible for those who opted into the content creator role and within the creators section is surely meant for creators to show off to other creators and talk about their creations/projects and work in progress -- not as a commercial advertising outlet to spam their marketplace links.
Discord forums support setting up posting guidelines.
Please empty it out and rename/recreate the channel to something else that would be more content creation focused sounding. (#projects, #work-in-progress, ...?)
Of course add posting guidelines that prohibit commercial spam and ban any marketplace links in the forums.
At least banning marketplace links, as well as any attempts at circumventing the ban (such as instructions or guidance towards product on marketplace or embedding the link in a product photo), and moderation reinforcement of that would at least quickly filter out most of the spam.