There was something reassuring that both had wanted to learn, even if they'd gotten themselves entangled in something dangerous. People shouldn't take the law into their hands - that was what Luther dealt with after all. But they should be able to take care of themselves, be able to get away from the crime before becoming the victim he'd have to investigate.
"You both catch on quickly," Luther said, before stepping backwards, in order to have more space. "There's one other thing that's good, temporary deafness is surprisingly useful." He held up a cupped hand, then gave an arcing swoop. "They say to swing it like a whip - aim for the ears. If you get can both, even better. It'll mess with their balance as well as their hearing. Grabbing the ear can work too - people are surprisingly sensitive there."
There was a faint smirk there - after all these years it was strange how he'd accumulated this information. An alley-way in Chicago with a potential informant had given him that. "You should have enough time to run, after this one. Give each other some room and try."