Yes I have used this method before, but it becomes pricey and does not always work. One time, after a severe hailstorm, my backyard was like pesto, and much of the squirrels’ regular food was destroyed. They were hungry! I had to sprinkle my tomatoes with cayenne, with mixed success. The squirrels were discouraged, but persistant. I even had a squirrel chew through my window screen to get to my tomatoes on the sill.
The same garden center which has fox urine also has a special capsicum seed mix, but I am not that desperate. With the safflower, I still get nuthatches, chickadees and the like at my feeder.
I’ve found that putting chili pepper flakes in the birdfood works, but you only have to use it if the squirrels come back. A flaming hot mouth keeps them away for quite a while, and whether it’s another or the same squirrel, I dunno. You don’t have to use the chili peppers all the time once the word gets around, at least in NJ.