The suet mix I make isn't something that's going to get in anybody's eyes or spill on the ground... I cut it into sandwich-sized blocks to put into the suet feeder.
I don't advocate wholesale dumping of cayenne pepper over everything... just too many problems that could result, as has been pointed out.
The squirrels here get plenty of food (we put a couple handfuls of sunflower seeds just outside the patio door every morning... "kitty TV" and entertains us too)... I just want to keep them out of the PB and suet feeders!
I suspect outwitting raccoons is even harder than outwitting squirrels.