The general consensus on the GRAINED Elforyn is that it's too inconsistent to be usable. Sometimes it's okay, but alot of it comes like swirly ice cream. I like the solid white, but neither look much like ivory at all and I wouldn't buy it as a substitute. Maybe it has improved, but the stuff with the grain that I have sits and will continue to do so.
The arvorin looks much more like ivory, but I doubt you'd fool anyone. It seems a bit soft, but polishes nice. I have not used it in a cue yet. I think Jim Baxter likes it in his joint protectors and a few have used it in cues, but I can't recall who.
Let me see if I can find a piece of each.