Peeps the crucial thing about using water as a deterant is that the pet
MUST NOT see you use it.
If your pet see's you using it then they asociate you with the scalding which will backfire. They will then be scared of you and not the act.
You need to spray them from round the corner or disguise what you do so that they assciate the act itself with the jet of water and not you.
Also it must be done simultaneoulsy with their action and not even a second afterwards. Again they must be absolutly clear that it is the action they are doing that rewards them with the water spray or again it will have little or no effect.Worse they will just think you are hurting them and that will break your special bond of trust.
You cannot spray them a few moments after the event as you might smack or chastise a child because animals will not associate the scolding with the event.
Sonya is it possible to construct something as an alternative ? it seems as though Ozzy is really enjoying the experience and nothing else will do ie corner of the bed and sofa lol
You could try pasting a double layer of wallpaper to a sheet of wood or plastic . It might work if its similar enough surface . Tell him if he's coming on holiday to the West Country this summer then he is going to have to pull his socks up and listen to his Mum !
Good luck anyway.