We have a problem with a cat spraying in the house. We have a ten year old (neutered) male but also get visitors despite a magnetic catflap.
I have no idea if it's a visitor or ours doing the evil deed.
I remember my mother having this problem years ago and buying a liquid cleaner that both cleaned the spray and put the cat off doing it again. It worked perfectly. Unfortunately neither of us remember what it was.
Does anyone have any idea what this could have been?