Can you stick a ghost in a Soul Jar?

My first instinct would be "no", because 1. ghosts aren't actually souls, 2. what's to keep a mage with only Death 2 from ending all ghost fights in one Clash of Wills -- Command Ghost, "get your dead ass in this here jar?"

But the Gaolers of Ialdabaoth in Grimoire of Grimoires are explicitly called out as using their first attainment to prepare a vessel to bind a ghost or spirit "as through the use of a 'Soul Jar' spell", implying that you *can* trap a ghost in a Soul Jar.

(That, and if...