I'm with FlaGriller (Jim) on this one. I never brine fish. Not even cheaper fish like catfish (although I VERY rarely eat them). Why not just enjoy the tasty Trout?
FWIW, to change things up, go to a local Spanish/Mexican grocery store and pick up some fresh/frozen Banana leaves - and wrap the fillet in one. Apply tasteful spices/marinade and seal the leaf and leave on grill for a little while. VERY good.