1.) You need a PE with a spam packet function.
2.) You need a computer that doesn't lag when spamming packets.
3.) You need a chat packet of any kind.
4.) If you used your brain to add those up, every player that was in your game might lag out from game.
I have not tested this, but I just thought up some of my of ideas for Combat Arms. Maybe it works, maybe it doesn't.
Edit1:
Oh.
Idea # 2: Blocking the damage packet for godmode?