Why would any church waste time debunking an insignificant religion like the Jehovah's Witnesses? It's not like they are losing significant numbers of people to them. The only people that need to be warned about Jehovah's Witnesses are the Jehovah's Witnesses themselves, and they won't listen to anybody.
Reminds me of the Emo Phillips joke:
Once I saw this guy on a bridge about to jump. I said, "Don't do it!" He said, "Nobody loves me." I said, "God loves you. Do you believe in God?"
He said, "Yes." I said, "Are you a Christian or a Jew?" He said, "A Christian." I said, "Me, too! Protestant or Catholic?" He said, "Protestant." I said, "Me, too! What franchise?" He said, "Baptist." I said, "Me, too! Northern Baptist or Southern Baptist?" He said, "Northern Baptist." I said, "Me, too! Northern Conservative Baptist or Northern Liberal Baptist?"
He said, "Northern Conservative Baptist." I said, "Me, too! Northern Conservative Baptist Great Lakes Region, or Northern Conservative Baptist Eastern Region?" He said, "Northern Conservative Baptist Great Lakes Region." I said, "Me, too!"
Northern Conservative†Baptist Great Lakes Region Council of 1879, or Northern Conservative Baptist Great Lakes Region Council of 1912?" He said, "Northern Conservative Baptist Great Lakes Region Council of 1912." I said, "Die, heretic!" And I pushed him over.