Whats best?

 

303 Fabric and Vinyl Cleaner, agitated very lightly with a soft interior brush and then extracted using a wet n dry hoover. The 303 product uses colloids rather than chemicals, and so is very safe for delicate materials. More info here...

303 Fabric & Vinyl Cleaner - 303 Car Care and Detailing Products

Just be aware that too much brushing and overwetting can damage delicate surfaces such as alcantara, so proceed carefully.

 

Thanks for that, will order some