It's perhaps one of the few places Klaus could have attempted such a thing without causing as much, if not more, discomfort than he is trying to fix. Although close to the lines of lyrium (and that Klaus doesn't seem to give them any particular notice, in fact, relaxes Fenris minutely), the pressure applied doesn't seem to bother him at all.

But he looks a little skeptical.

"That's it?" Then, a moment later, with careful curiosity: "Does this work on other pain as well?"