We used to have a little Patterdale terrier and I had an Ikea large fluffy rug that looked a bit like grass and when you walked over it you found little wee puddles, I spent a fortune washing with all the products mentioned, we bought plastic carpet covers and wee pads (he wee'd on them then ripped them up) When we moved I took out the rug (it was expensive too) and the Amonia smell could have brought someone out of a coma, so we had to throw it away, thats the only answer, I trawled the internet and looked in pets shops etc for the solution but everything seemed to make it worse, just have to throw the wee wee bit away and prevent the dog getting any where that it may wee......I bet hospitals and O P homes, hostles etc have the same problem, I use bleach for outside and the bathroom and that seems to de oderise rather than smelly things...good luck!!!!