According to a 1986 WT arcticle if someone sincerley asks about the claims of apostates then JWs can respond using the scriptures as well as society publications. Hense using this arcticle you can defeat some of the source attacks by JWs using the "that comes from Apostates, so I don't have to consider it" defense mechanism.
Using original Watchtower Literature is best, especially the complete page of the quote therefore the "out of context" argument can be defeated.
flip/flops are also good for dealing with the "new light" getting brighter arguments. for example the men of sodom resurrection teaching which has been reversed multiple times.