I would have responded with 50 pounds of sugar beet seeds in his nicely manicured lawn.
After a particularly nasty "prank" that cost several hundred dollars to repair, I once responded with writing nasty things in the culprit's lawn with about 10 pounds of well oiled sodium, shortly before it rained.
Thank goodness the statute of limitations expired on that one many years ago.
Mark
Actually, that's what we did at the stadium. We poured the seeds in the shape of our school initials. Those poor souls didn't realize it until the following fall.
One other particularly nasty trick is (just before a moderate rainfall) pour a few bags of cement on a lawn in the shape you want. Let the rain do the rest of the work.
Salt works better, and if you don't pour out too much, you can write a clever phrase or two on a lawn.....but it will be gone by the next year.
If they have a front lawn with a slight rise, its even better. Passing vehicles can see your "slogan" for the target of your wrath.
Its also very effective a week before a football game away from your home field, btw......LOL!