A few months ago in the summer, we were plagued by cats pooing on the gravel on our patio. It because a giant cat litter!
I was beside myself because I don't like cats, and the thought of cat faeces everywhere was really winding me up.
i bought 3 bottles of lemon floor cleaner, dettol lavender and lemon fragrance and a few packs of anti-cat poo granules.
firstly every time there cat poo, you have to remove all traces of it, wrap in newspaper and bin it.
then I hosed the gravel with fresh water.
then half filled a watering can and top up with Flash lemon floor cleaner and water it over the whole patio.
then sprinkled the anti-cat granules around the edge of the patio and lots on the site where the cat had pooed to eradicate its smell, so it wouldn't find it again,
after about a month, the cat must have got fed up and went elsewhere.
it was awful!