Flossing is necessary for those super tight contact points as you see in the above thread, and is great to remove plaque down 1 mm deep in the gum line (gently).
InterDental Brushes are fantastic and go down 2-3 mm into the gum line to remove plaque.
They basically go back and forth with InterDental Brushes on which is better as far as being the top of the food chain for overall cleaning of the space between your teeth.