They are designed to be thrown out; but apparently they heavy and need somebody strong to pick it up; weight like 25kg or so.....
The real reason they wont let you fly emergancy exit, is your leg could potentially block the exit.....
That's why they make a sepetate breifing just for the guys sitting there....
I'd say speak to the airline, see what they say,
I'm sure the lcdc wont like it, and tell you to fly saa