I never had problems cleaning wool carpeting. In fact, IMHO, they were the easiest to clean. And, they dried relatively fast.
In your particular situation, I would write out the specifics on paper and have your customer sign it releasing you from any legal responsibilities based on the faulty installation(s), etc.
When and if you do clean it, I would use a fan or two to provide much quicker drying.
Just my advice and opinion.
The JAGUAR MX-2 ETM @ crossamericancorp.com