It may be more effective to manipulate your brother into making a statement that you know that the WT contradicts, then putting the onus on him to do the research to prove the statement to you.
JWs think that they have all the answers, so instead of confronting them with a statement that you have to back up, ask a question that you know they can't answer, then use guilt and their own self proclaimed despise of double standards to keep them honest and on topic when they try to weasel their way out of an honest answer.