I fired some 9mm 124gr EFMJs into very damp telephone books and compared them to 115gr and 124gr ProLoads.
The EFMJs would go through 5 telephone books and usually not expand evenly. Is this because they're supposed to expand only in water?
Water doesn't support a shear force as does human soft tissue and properly prepared ordnance gelatin. I haven't tested EFMJ, but from the data I've seen, water appears to be an unreliable medium to test EFMJ expansion.
As for your damp phone book test media, without a more detailed description of your results or a photo of the recovered bullets, there's no way of judging if the performance you observed is good, bad or otherwise. Perhaps your damp phone books weren't completely soaked?