All depends on the fabric really, some fabrics are not suited to wet cleaning, such as viscose rayon,velvet,velour. Get yourself an angle drill and drill brush, this will make the agitation part a lot easier and quicker, make sure the drill brush is for upholstery though, not carpets. As for chemicals ,depends on the level ,of soiling, for heavy soil use Chemspec formula 90. Half a scoop to 5 litres of hot water.