and buy yourself a little free time for yardwork.
Go to your hometown Hardware Hank and pick up a few of these spray bottles, then go home and turn the kids loose. The bottles cost less than a decent squirt gun, have a good range, don't have to be refilled every two minutes, and feature a cool mist setting.
When the kids are done squirting each other, they move on to semi-productive things like blasting anthills and pretending to be firefighters. Lots of burning bushes around here (though none of them have delivered any particular messages).
Bonus feature: pick up some sidewalk chalk too, and they can spray their drawings when they're done.