Citronella is something I have never tried, but if you're looking for a cheaper solution, you can try a few moth balls on top of the soil. They don't like the smell, it's harmless to both the plant and the cat.
I have an old country vet and he suggested once about my own mini schnauzer to take about 4 or 5 paper matches and wet the heads with your saliva and insert them into the dog's anus. It's a trick used for show dogs, so if anything is in there it will happen in the … Read more