Your brother sucks. Teaching him full-frontal fighting is like teaching him how to lose in Vietnam and Iraq combined.
So what, the guy gets beaten up once POSSIBLY? Where's the fun in that?
Character assassination and alienating his friends is where the real fun is at. Stalking and leaving his family notes is also another fantastic way. Failing all of that, kidnap & rape him. Be relentless at guerilla tactics, rather than being a fag and engaging in some white-collar homoerotic Fight Club.