Slayers Stone: "When you apply a slayer’s stone to your weapon, choose aberration, animal, beast, celestial, construct, dragon, elemental, fey, fiend, giant, monitor, ooze, or both fungus and plant. A weapon under the effect of a slayer’s stone deals an additional 1d6 precision damage to the creatures with the chosen trait or traits for 1 minute."
Oozes are immune to precision damage.
If this is meant to be something like the Bane rune, that rune does extra damage of the weapon type. I wish this was caught before publication. It's another example of products that maybe don't get as much time with the editing staff as needed. I caught this just in a casual reading.