Maybe have a referee that you show the sources for all your facts to in advance of the debate. Then if at some point during the debate someone says something that wasn’t confirmed with the referee in advance, the referee would interject something like “That’s unconfirmed” before allowing the debate to continue. Edit: It might be best to have a team of referees made up of folks from both sides of the debate and maybe a few unaffiliated folks to help everyone keep in mind their purpose and break ties.
Maybe have a referee that you show the sources for all your facts to in advance of the debate. Then if at some point during the debate someone says something that wasn’t confirmed with the referee in advance, the referee would interject something like “That’s unconfirmed” before allowing the debate to continue. Edit: It might be best to have a team of referees made up of folks from both sides of the debate and maybe a few unaffiliated folks to help everyone keep in mind their purpose and break ties.