I re-use substrates when I am repotting. Same substrate used for the same tree - for the most part. In the past I would take all old substrate from healthy trees and mix it all up and then re-use it. With inorganics, healthy trees, healthy soil and large grow boxes or Anderson flats, I saw no problem doing it. I also had no issues doing it.
This year I replaced 100% of my substrate, as it was a couple years old and time - regardless of the condition, I wouldn't reuse it more than once. Oil Dry was a prominent component of my older mixes, and like akadama, it does have a relatively short life.
Note: I got blasted on BT for saying it is ok, within reason, to re-use substrates. So, take it from me or take it from one of the much smarter people that told me I was a fool - your choice.
Another note: Yes, I said substrate. Walter hammers us on calling it substrate, as these mixes do not contain anything that would normally be considered soil. That said, around the house I tell my wife I am going to go make up a new batch of dirt. She seems to know what I mean...