I had a family of cats take up residence in my garden shed. I have similar restrictions on getting rid of them, so I purchased a 2lb bag of fine ground pepper and sprinkled it liberally around the shed.
It took three applications but no more cats...
Thank you. I know that fox urine will work but it washes away quickly and is very expensive. I tried washing my porch with Pine Sol, which worked for two applications but if it was not done twice a week, it was worthless. How often did you have to wait between pepper applications?