I just found something out- you can, I realize, grenage drop by grabbing. I can't make it work 100% of the time, but you can pull out a grenade, grab them, which drops the grenade at your feet, then throw them any way but down (up only works if they have around 100-150 damage [for a character with Diddy's weight, I tested it on him.] on them, but if the grenade hits them after you throw 'em up, it's a kill, far as I can tell.), pick up the grenade, wait, until they land (except for the up-throw), and throw the ready-to-blast grenade at the enemy, defenseless, as the were just thrown.
EDIT- I can't seem to make this post actually post. How odd.