I use VAX pet solution, diluted as per instructions, in a spray bottle. I also put belly bands on, it doesn't take long for them to realise there's not much point in marking if nothing happens.
Don't wash his lovely, smelly little bed, he likes it stinking of 'him'. He will grow to recognise the smells of the house as 'his' smell, and stop marking eventually. Until then, belly band and get rid of all the old marking smells. Marking behaviour is for outside, not inside.
I used vanish stuff on my hall carpet for the same problem. It's a powder comes in a bag that you shake onto the carpet brush in and leave for 20 minutes before vacuuming it up. You do need to be quite spring with the powder I put loads down the first time but as it's damp it clumps a bit so when you brush it in it separates so goes a long way. I was sceptical but it took away all the big circles of watermarks from cleaning up dog pee on my (stupidly) light carpet.
Simple Solution soak up as much of the wee as you can possibly get out of the carpet then absolutely saturate the area with the SS.
An alternative is Bio Washing liquid or powder, made up with very hot water into a good strong solution and treat as above.
You need something to completely break down the biological elements - hence the need to saturate the area. I saturate the area, then work it into the carpet with a nail brush to make sure it gets right through the piile. The most common mistake with pet accident cleaner is not using anywhere near enough of it.
Thanks for the suggestions guys. Hoboken I've tried various sprays before with no success, so might go with the vinegar suggestion - sounds weird but I'm pretty desperate! Will my living room end up smelling like a chippy though MissCPH?
Our otherwise lovely rescue dog of about 5 months has never quite grasped housetraining; I do my best to clear up after him but our living room carpet looks horrendous, with water/wee stains all over it. Quite frankly it smells too, which is disgusting, and I'm turning into a hermit as I refuse to have visitors round. Currently using biological washing powder in warm water to clean with as recommended by the vet; it's clearly not working, can anyone help with a foolproof method of getting wee stains out of the carpet in an effective and hygienic fashion?