For future reference, there is! Itch's tools for doing it are just really clumsy and hard to find: https://davemakes.com/extremelyspecific/blog/20250927-running-a-game-jam/
The rest of that post has lots of other handy advice, but TL;DR for that specific bit: First, report the entries (...to yourself, haha), then open the reports (edit jam -> moderate -> reports) and select "Dismiss and ban account" as the moderation decision.