This is an ongoing problem in my garden, there are at least five cats from around the neighbourhood that come into my garden, mainly because of all the birds that I encourage with feeders hanging in my Acer tree. It’s very difficult to nail the furry shitbags with a supersoaker, because the tree and two sheds divide the garden in half, with a patio immediately behind the house, and the small lawn and a patch of garden the other side. The tree is getting on for ten feet high, and almost as wide, so shooting anything through it isn’t possible. They have crapped on the grass, and on the garden area, breaking off freshly planted Fritillaries, which I was very annoyed about.
One cat killed a pigeon last year, and almost killed one of last year’s young blackbirds as well.
They’ve also been swiping the food I put out for the hedgehogs, which I put under a large paving slab on bricks, but I’ve changed that to three plastic boxes with a small hole in the end of each, arranged so cats can’t get into them.
One way I’ve found of scaring them is lobbing those little fun cracker things out of the landing window onto the patio, but it’s only temporary.
I might try the pepper, maybe with hot chilli powder mixed in, to see if that works, but at least one of the cats comes from the flats the other side of my fence, the owner leaves the top window open for it to go in and out, so it uses my garden to shit in. 🤬