The problem lies in ensuring no one else can remotely flick the switch.
This is why the switch is a physical one, no?
Thing is, if you want to airburst it, it needs to be wireless-enabled.
Because really, pointing a laser at a receiver on a tumbling grenade? Good luck.
Alternative: voice activation! With a slight timer.
Throw grenade.
Shout "BOOM!" with an explodey arm motion.
Watch goons give you a look as if you're the craziest man ever and point their AKs at you.
Take cover from body-shrapnel.
????
Profit!