Do you clean them out after each smoke (after they cool down)? I'll get an argument going possibly, but my understanding (and it has worked for me) is that you should scrub them clean after they cool down (don't build cake). Do this from the beginning and there shouldn't be any ghosting. Same with clays. It's one of the benefits of smoking meers and clays, over briar.
As far as those who have said they receive ghosted estate pipes that they can't get the ghosting out of - I don't see any issue with just sanding the inside of the chamber until it's free of any old remains. I wouldn't do that with a briar, though.
Okay, I have tough skin - fire away