The upper body sets you up for the kick. There is no pause in the breaststroke. Dropping the knees stops you dead. Move forward in the in-scull, do not drop knees, don't pause. Bring feet up to butt, don't drop knees.
Correct motion is simply a scull.
Explode forward with hands. Never turn palms up. More speed comes from increasing your speed. Go quickly into the next stroke. Kick with the toes out wide.