When I did my sis-inlaw's house, I sprayed Oban after I was done to freshen up the place. I sprayed onto the carpet and in the air. 2 dirty dogs there. The next day, my wife went over there and said she smelled dog on the carpet again. Like I said in an earlier post, the carpet is only 1 1/2yrs old but was filthy and I used a good amount of pads for 300 sq/ft living room. Should I have worked the oban in with the challenger, or woould that have just brought the oban off the carpet and also more soil since the oban would be wetting the carpet?

In a pet odor situation, I mix some Oban in with the cleaning solution. But if an animal has been continually peeing on a carpet, chances are the pee has migrated well down into the base of the carpet. It could possibly have gone through the base down into the carpet pad underneath. There is not a lot you or anyone can do about this deep penetration of urine.
You might go to a pet supply store, or a janitorial supply outlet, and buy a black light. One of these will help you to locate the urine deposits. You can then apply an Oban/water mix directly into these areas, and hope to get it far enough down to kill the odor.
There are restoration services that will send in a crew of 2 or 3 people. They will first take the carpet off the tack strips that hold it down, and then roll it back, looking to see the blotches in the underside of the carpet caused by excessive pet urine. They will then spray their own odor neutralizer onto these areas - heavily! Then they will look for urine splotches in the pad beneath the carpet, and cut out these areas of the pad, replacing them with new, clean pieces. If urine has even soaked into the wood subfloor, they will either sand it out, or seal it over with acrylic or polyurethane. They then place air blowers in the room so that everything can dry overnight, and return the following day to remove everything. As you might guess, this can be an expensive experience, and might just cost more than totally replacing the damaged carpet and pad. I don't do this type of work when I encounter this type of situation. I just inform the customer that such services are available. The price of allowing an untrained dog to roam through the house can be high.

I am a fan of OBAN.

My two cents is that maybe you didn't use very much of it. To cover a whole living room, especially a dirty one that reeks of dogs, I would put maybe a cup of OBAN into a gallon of the cleaning solution that I was washing the rug with. Then I would probably spritz some into the air after the washing was all done.

If the odor was originating from urine, Nature's miracle works well, if you can identify the spots.
If the urine is widespread, forget it... You need the restoration service that Mark mentions.