IF one were able to get flashbangs or a reasonable facsimile thereof legally, i can see a valid use for them. besides the fact that they'd just be loads of fun for new year's eve and the fourth, during a breakdown of civil authority such as has been experienced during large scale riots and natural disasters (like every time the raiders lose.... or win) police will not be able to respond to your house. the most accepted tactic for dealing with home invaders is to hole up in a "safe" place if possible with your family and call 911 to let the professionals deal with the problem. if there will be no cavalry available, it will be your responsibility to clear the house on your own. i can see how having every advantage possible would be a GOOD thing. room clearing should be done by at least a four man team but two can do a pretty good job if necessary and a flash bang sure would help to clear large areas or complicated rooms.
i tell you that i have no intention of going "quietly into that good night." i will fight with every tool and every second of training that i have. if there are no professionals available to relieve me i will be forced to take the fight to the enemy. heck, i bought some smoke grenades, mostly for fun, partly for rescue if stranded in the desert and, maybe a little bit because you never know when you'll have to move across an open area under enemy fire
smoke grenades put out ALOT of smoke, too so you could even use them as a sort of ad hoc cs gas - the smoke is a mild irritant and when concentrated it really sucks. plus, if i throw one of the yellow ones at some ignorant bangers, they might even think it's mustard gas or some such; of course, if i'm wearing my promask while i do this, it might lend credence to the illusion
okay, let's face it: i think everyone hear absolutley adores just about anything with "grenade" in the name and regardless of the real practicality, it sure would be FUN to play with flash bangs, smoke, incendiary, even a genuine m67 grenade, hand, fragmentary would be a real hoot. who wouldn't want to impress the guys at the range with a case of grenades? sure, you gotta throw 'em BEHIND the berm and you don't get to watch 'em go off, but it would be FUN, right? right? okay, maybe it's just me. and i thought you guys ENJOYED blowing stuff up and making loud noises.