Okay, I didn't make it clear, but it should be possible without actually killing someone from your own team.
That's just chaotic, haha
It is possible without killing (too many) teammates. I play whole evenings with it turned off and don't get kicked. Sure, there is the occasional tk here and there, but it actually also makes you more catious in clusterfucks.
As a melee, you can always aim at the dude and if a name pops up, it's a friend, otherwise kill him. As a ranged, you shouldn't shoot into melee anyway, so pick the obvious targets (like those running straight at you with a stab chambered). Once you can't tell friend for foe anymore, grab your melee weapon and do it like everyone else.
Just give it a try for an hour and see if you like it.