with rikku and lots of luck, you can steal purifyign salt from any zombie at zanarkand.

a weapon CANNOT have no encounters on it.

and i forget its name, but its a giant fossil thingy in the omega dungeon, and it rarely drops armor with no encounters on it. and i used it for cactuar village and thunder plains side quest as well

hope i helped. if anyone remembers fossil name thing, glad to help.