They're noncorporeal, so it seems like the spell should work. But it doesn't!

Your fingerbones phosphoresce hylomorphic blue as you gesture at an ichorous yellow-black spectral reaper.
Drops of tarnished, metallic blue liquid fall sideways toward the spectral reaper.
Before they can reach the spectral reaper, the drops lose cohesion and fizzle away.
Emotional pain and exhaustion lingers in your mind, even after you regain rational control.
Roundtime: 1 sec.

Mazrian

Should have had a grounding field in place to protect from that burn. =/

Mazrian