Carpet bombing was a WWII tactic that American bombers used long before the days of precision "smart" bombs. Basically, hundreds of bombers would saturate a general target area destroying everything in the vicinity rather than aim for one precise point. Leaving aside the question of ethics, it got the job done. It was messy, but it worked.
Applying WWII bomber tactics to raccoon trapping may not be intuitive to some, but let me explain. If I find an area that I have not had a chance to scout, but it looks "raccoony" to me, I'll follow my hunch and put in some sets. If I don't find specific spots with sign to target I'll simply put in several quick sets at even intervals in an attempt to "carpet" the area. This may not seem very efficient, but if your hunch is right and you connect with a few coons, you will quickly learn where to focus your efforts.
Here's an example. The map below is of a pond and swamp where I tried this tactic. The red dots represent my initial set locations. I simply set the various points of the pond at even intervals with dirt-hole sets on the bank. The first two nights I caught one coon on the north point at the bottleneck between the pond and the train tracks, and two coons on the east point at the tip of the small peninsula. The other three sets saw no action, but after two nights I knew where to focus my efforts. I pulled the inactive sets and doubled up my sets where I was getting the action. "Carpet bombing," as I like to call it, is an exercise in narrowing down your set locations by a process of elimination. You start on a hunch, saturate the area, then narrow down your efforts to where the action is.
Maybe it's not the most efficient method. Setting on sign in well-scouted area is always best, but if you're setting a new area and time is short, try carpet bombing.
(click to enlarge)