Honestly freeing Mogget hadn't even crossed Eames' mind; he's likely bound by something more powerful than your average spell and Eames wouldn't really know how to go about undoing that. Maybe if he could get Samantha's full name, but even then it may not be hers enough for that to work.

"She offered me a bond, of 'trust and friendship' she said," Eames says with a scoff, "I suspect she conveniently forgot to mention 'magic and servitude' when she suggested it."