Heres a little trick i've found waterfalls more manageable, don't use full power all the way round as the inertia will build up and make recovery difficult. Basicaly only add power (not always full power either!!) when the nose is pointing down so it can kick the tail under. Have you tried putting in right rudder as you add elevator as this can sometimes stop it torque roliing on the exit??
Just an idea, it works for me!!