Cats crapping on my lawn

[bodgit]

Next doors cat has started crapping on my lawn and the dam thing has diarrhea. For the last three night it crapped three times on my back lawn. I've bought one of these from ebay 230691198405 the thing is supposed to emit sonic noises to scare it away.
They have 6-7 cats which is way too much for anyone and since my dog died we have had the dirty B******* peeing on the front door and five times in my car air intakes which stunk my car out for days.
Anyone know if those sonic things work or any other way to keep them away.