Agent23
Ни шагу назад!
Yeah, ok, sure, sufficiently advanced tech...Turning someone into a wraith is not "chemistry". We are not talking about a weapon that will kill you. We are talking about a weapon that will make you.. ahem... not die at all.
I remember what stabbed Frodo, and iirc that stuff was spreading through him like some disease or cancer.
The truth is that the Dune verse is quite advanced, it is their feudal system and all their conventions and prohibitions are what limits its usage.