Defenders cat repellent granules are made from natural garlic extract and aromatic oils that cats dislike. They are designed to be scattered on paths, lawns and flower beds to keep cats away. We found they worked in some areas and not in others, with some cats seeming to ignrore them entirely.
While cheap to buy you cannot cover much area with one container and they bio-degrade after a few weeks. This means in the longer term a water repeller or an ultrasonic repeller will be more economic and more effective.