Go around the neighborhood knocking on doors. This is you best bet. Obviously there is a variant with RSSI measurements, but in the neighborhoods with a lot of networks and multiple walls, that usually does not help. To be honest, you walking around the neighborhood with a laptop and antenna will freak the kids out much more then some offensive network name.
Seriously, I recommend you to just leave it alone. Get over it. This network ID does not contain any curse words or directly offensive language. In fact, even if it would be offensive, then you could not do anything. WiFi names are not regulated by any law as far as I know (this subject is mentioned/discussed here and here)
And even if you find the owner, there is nothing you can do about it. I am pretty sure the owner of the network will turn out to be some 16-year-old kid with a specific sense of humor. And I recommend you to get away from the PC and spend more time with kids instead of worrying about cyber bullying - this would really help.