Efreeti Bottle (Cespenar)

The Efreeti Bottle, not to be confused with the Efreeti Bottle in Baldur's Gate II: Shadows of Amn and Baldur's Gate II: Enhanced Edition, allegedly summons a version of Cespenar to build and upgrade items.

But I can't find any reference to this item in the game files, so it may be cut content? Various forums say it was used in The Black Pits and/or The Black Pits II: Gladiators of Thay, but I couldn't confirm that, either.