I have the same problem..I usually have the living room blocked off...but someone moved the block & Jack got in there a couple of times....well, that's all it took.....he couldn't resist.....I first tried an enzyme cleaner from the pet store...then Bissell carpet cleaner for pet stains..then Resolve...then a mix of white vinegar, dawn & borax ...& finally straight vinegar. THE SMELL IS STILL THERE!
I figure the stain is set permanently now...I will have to tear up the carpet...I hated it any way...no more carpet for me.