Or take advantage of incredible gobbie stupidity, and do the whole "DANGEROUS TRAP FILLED HALLS OF DOOOOOM WITH A COW ON ONE END! Any tamed animal will do actually, but damn, they'll go after it. Best you can do is take the pet from a dwarf who's died, still named, but when it dies no unhappy thoughts =D win!
Anyway, they'll go for it even while marching through weapon trap after weapon trap after weapon trap (or stone fall traps, if you build your fort right you can prevent the mechanics from going to fix them), as well as ballista fire. It's quite funny actually. Especially since if ya build it right, even a 90 goblin invasion can't get through. They just keep getting owned by the ballistae shots and other awesome stuff. If your map is wood heavy don't bother to carve trenches near the walls. between corridors, if your map has no real wood and you're totally dependant on traders, seriously, take the extra time, dig the channels. It'll save enormously on costs and you can also make it impossible for your dwarves to go after it in an emergency. Make sure to put fortifications in for the ballistae bolts to pass through, otherwise you'll have trouble.
This is almost surefire method of totally destroying the enemy, or at least killing enough of them that if they DO have survivors, they'll run away. Best part? it works on all races and attacks.