The truth is, you're not removing whatever is causing the spot in the first place. As a matter of fact, by using too many chemicals you will make the problem become very complex and worse than it was to begin with. 

My first recommendation would be to simply spend a fair amount of time rinsing and extracting the area very patiently and do your best to remove every ounce of cleaner, product, urine, etc.  leaving the fiber virgin, and then applying your fan. This could mean extracting the area as much as 20 or 30 times SLOWLY so that you can let water, the most amazing cleaning product in the world, do its job. If after you've done all that you still have a re-soiling problem, odds are good something is wicking from below the surface such as the backing or cushion because of an extended dry time. 

The best short term fix would be to clean the surface of the carpet using a low-moisture method such as a bonnet and a neutral cleaner and dry quickly, and as quick as 5 minutes which will keep the re-soiling from happening. 

The correct way to fix this would be by using a water claw extraction tool and flood the area and extract it multiple times, using extremely hot water. Or, to pull the carpet out, replace the cushion, and rinse and extract the carpet from the back and re-install the carpet.