ive found the big black scissors that u get with kitchen/filleting sets work a treat, the ones with the big blades, its kinda hard to explain. i think mine are force ten from kmart or something, i got them with my filleting set. they work well on fireline. as the action is more of a crush and sever then just slicing, i think theyed work better longer. due to this action, you have to put some tention on the piece ur trying to cut, but thats fairly standard anyway.
hope that helps
cheers