I can also vouch for 1001 carpet cleaner diluted big time in a bucket of hot water, i have cleaned a few seats especially with this stuff, agitate yes but depends on the fabric and what to use, i have just done the seats in my A3 (jacquard satin) and they can take a stiff brush but with the seat quite well soaked, i then use old towels to soak it out i don't like using a wet vac as it pulls too much crap out of the seat foam, the towel is gentler. First time i used 1001 was on some pale grey polo seats on a car car in cyprus full of sweat, dust and sun tan oil they came back like new.