A beard and mustache trimmer would work well in that area. He might be scared of the noise at first, but maybe if you just let him sniff at it while it's on (Not near the trimming end, of course
!), he could get used to it. Try to do this when he's very calm.
Luna has those crazy hairs too. My groomer took her with just her first shots in her, as long as she'd had the bordatella vaccine.
Good luck!
