Tali can be an absolute bugger for generate "perfume", but it does seem to depend on what he's been scoffing, cheap wet cat food seems the worst. Luckily he hates going to the loo when being watched, so often does it at night or when I'm at work. Generally he's an outdoors cat, so I assume that the flower beds suffer accordingly, but that's not an option when I'm cat sitting him.
My sisters two indoors only show cats have an electric, self clearing tray. After one of them has used it, a rake arrangement motors through the litter and deposits whatever it picks up into a plastic bag at one end of the tray, before closing a lid on it. It minimises having to be associated with the stuff, as well as smell proofing it to a degree.