Our intrepid hero works in an open office, within a short stone's throw of the IT Support Desk. They fool around every Friday (and most days between Friday and the following Thursday). The inane chatter and laughter is annoying and disruptive.
How can our intrepid hero create a hand-thrown silence grenade over the weekend?
Constraints:
- Area of effect should be 10 m$^2$
- Despite calling it a grenade it need not explode in the traditional sense
- Should incapacitate those in the blast radius for ~ 8 hours
- Fits in the palm of the hand and can be easily activated and thrown
- Should have a delay mechanism...I don't want to knock myself out
- Cannot be fatal/cause long term damage (I hear prison is pretty loud too)
- Should not require any ridiculous future tech or military grade components
- Works.
Desired Effect: Silence until 4:30pm at least.