I certainly wouldn't "presume" that I wasn't going to get hit in any clinch, Judo or otherwise. It just makes it more difficult for the opponent to do so. While my Judo experience is minimal (2 or 3 classes, I think), the Judo grip can be used effectively to keep the opponent unbalanced.
As long as they are off-balanced, it will be hard for them to hit you. Please note that ALL of my clinch skills suck, lol.
"In case you ever wondered what it's like to be knocked out, it's like waking up from a nightmare only to discover it wasn't a dream." -Forrest Griffin