They promote safety collars Stu that would break at a weak spot before they would choke a cat!
Talking of crapping, that is the main problem with cats, they ruin efforts at gardening.
I have a tried and tested answer though. Orange peel. Cats cannot stand it. I put it around my plants and it keeps the buggers away! Another on is short pieces of cut up hosepipe. This has two uses. Apparently, cats think they are snakes, and they have the advantage of the fact that earwigs crawl into them at night and can be disposed of the next day.
Bloody hell I am starting to sound like Titmarsh.
Oh don't be silly, what do I know about Geology !!
;-)))