Bring a video camera and tripod to the games.. If it starts up, you can point it at the other dugout and or their parents.
Let the coach know you'll make him/her an Internet Star if they don't control their players and parents.
truth be told, I'd probably pull my girls off the field. I coach 10u rec, and I take the "rec" part of it very seriously. Not sure what I'd do if it was a more competitive league