You could always state that the encounter occurs towards the end of the Rod's 500 minute control limit...that way, there's little harm in the PC's acquiring the item - all they can do is sell the parts for scrap, as it were.der_kluge said:Well, because the PCs would acquire it once they kill this particular BBEG. That's not something I'd really be comfortable with them having.
That, and by a strict reading, "dominate monster" won't work on oozes, even though the item description doesn't specifically state otherwise.