Even better, use the "turn in all" button from the Ishgardian Restoration approval UI.

I like this idea a lot, though, since I might have something in my inventory I don't actually want to turn in, but haven't put on a retainer or in the glam chest just yet. And the stupid "YOU DID IT" window doesn't need to flash every single friggin time I hand them a piece of dungeon gear my retainers found on the beach.