I keep jars of Cayenne on hand for varmint control. When squirrels, rabbits or whatever start to gnaw on things around the property I mix it with hot water and brush it or spray it on. I've never seen their reaction but I'll bet it was a sight because they never try again.
There used to be a skunk that would come by my house in the wee hours and dig thru the flowerbeds looking for whatever it is that skunks eat.
It would then spray the house and leave.
This happened about 5 or 6 times and I *really* wanted to do harm to that critter.
A relative suggested red pepper. So I went to a restaurant supply house and bought a huge jar of ground, red pepper. I mixed it in thoroughly with the mulch.
Next night, Mr Skunk got a snoot full and took off - never came back.