yeah aparently though it does really work as i was told it is not a normal noise they will be used to.
suppose it depends where you live though to be doing this.
Cant see people complaining if they can see the reason you are doing it.
I wouldnt complain but people are very different.
the only other thing my mum used to do was to get a cat harness and walk our cats around the garden so they have more time to mark there terriotory.
All of her cats now only stay in the garden.