You could try Microban.
The same happened to me years ago, couldnt get rid of the smell, wool carpet in master bedroom. As I was with SM at the time used all their stuff, cleaned it again rinsed it again, dried it dehummed it etc etc, all to no avail.
In the end we agreed it would go and it did, sort of. Nice people, nice house etc etc so not really a prob.
Couple of years later I was at a place that was just opening and Chemspec were the preferred suppliers, rep was going through his stuff, yadderr yadderr etc etc.
'Any body had an experience where wool carpet smells of sweaty socks?' Up went my hand, no body else knew what we were talking about.
He said Microban is the stuff to use, as its a fungicide, biocide, deodouriser etc etc it kills everything, but isnt dangerous. Well unless you drink it of course! I use it all the time now on anything thats dodgy, blood, vomit etc. I show people the label and they see what i does and its not so dangerous.
Actually to go off on a tangent, while I was working on the customers smelly carpet and other things there, I saw loads of his diplomas, citations, pictures of him with Maggie letters of thanks etc etc. I met him a few times and according to his wife he used to be in Special Branch when 'The Troubles' were on in Northern Ireland, and he was working under cover over there, so he wouldnt look suspicious, he had to put 5 stone on to be overweight so he didnt look like super fit SAS type. And yes he had lost it all again whem I was working for them.
Murky