A couple of years ago we were driving from Washington to Arizona and had our dogs in the back seat of our Ram Power Wagon. The back seat was leather with millions of tiny holes to match the front seats which had cooling. We drove through a Starbucks and my wife decided to try a "Puppychino" for the dogs, which is just whip cream in a cup. The dogs loved it, but unbeknownst to us, our Lab is lactose intolerant. About an hour later it had diarrhea all over the back seat. It was a nightmare.
We did immediate cleaning with various leather cleaners from O'Reilly auto parts, but the truck still reeked. We couldn't use the enzymatic cleaners because they apparently will damage leather. We finished the drive with windows cracked and noses plugged, and when we got to Phoenix I took the truck to a highly rated detail shop. I can't remember exactly what I paid but it was around $600.
The special cleaning from the detail company seemed to have worked until the first time the truck was parked in sun for a couple of hours. At that point the diarrhea stench returned mixed in with all the cleaning smells. My wife then spent about 20 hours with soft bristle brushes cleaning all the small holes. That removed 99% of of the smell. But the remaining 1% was unpleasant enough that I had reached the point where I was going to buy a new rear seat. For other reasons though we then decided to just trade in the truck.
Hopefully you have better luck than we did.
