Go to a local hardware store and rent a carpet cleaner for the day. Along with the normal carpet brushes you should also get a smaller tool used to clean hose furniture upholstery. This is one of those machines that sprays a combination of very hot water and non foaming soap, it also has a vacuum or suction function that removes most of the applied water/soap along with large quantities of dirt. i don't know where you would find a rental place where you are but where i am in British Columbia, Canada we can rent them at hardware stores, some grocery stores and probably even at Home Depot. Ask around. We have used these machines for carpet and seat cleaning in all our vehicles with very good results.