Can anyone recommend a very strong cat repellent? I have a gravel driveway and the many many cats in the area, think it’s a giant kitty litter! It’s become rather problematic when arriving home in the dark and finding out I’ve trodfen cat crap into my hallway. I’ve tried 3 cans of pest repellent from the local hardware store.. but it’s not doing the job! I need something a bit stronger. Can anyone recommend something that works? I’d really appreciate the help.