isnt it strange how whenever the subject of peeing on things is raised, we end up with a really long discussion, popular subject!
im with muntjak only really effective detterent is a lead slug. Used to be able to get special airgun pellets for shooting cats years ago as well, i had a box of 'catslugs' once, also had an oil and greese free co2 powered airgun that fired the silver edible balls used to decorate cakes. It was intended for pest control inside food preperation areas :shock:
rather than deterence, perhaps defence is the better option. A good fence, anti-dig measures etc, ive yet to see a fox that can use wirecutters :?