Not sure about the idea of involving other religions, as doing so may be seen as a conflict of interest on the part of the churches involved.
Yes Pete you have a very good point.
I think letting the religious community know about Watchtower's cruelties generally is good, because people with a belief in GOD are obviously more vulnerable to being converted.
But - as yourself and Steve 2 mention - a ' rent a crowd' from competing churches would detract from the message, and give Watchtower ammunition against them.