Ahem. We have a whole
book on this stuff.
Number 28 Use of the Knife: Judo Grapple/Face + Knife Thrust/Neck Arteries or Knife Thrust/Vitals. And I quote "The grapple serves to hold shut the target’s mouth." A Targeted Attack (Knife Swing/Neck) is treated as "cut the throat." It also notes that these can be "applied using All-out Attack (Double) or Rapid Strike " as well as
Martial Arts combinations.