First, you need to make the repair in you sewer line to get rid of the sewage. Next, try to get the sewage out of the crawl space, usually you can get it to run over to the foundation footer. Since most footers are stepped down to get to the lowest corner, try to get the sewage to run to that point.
It may be necessary to rent a hammer-drill and make a hole in the foundation at the low corner to drain it out. Use the largest bit you can get for the hammer-drill.
With the sewage gone, you can dust the space with hydrated lime to speed the decomposition and cover the smell. Then you will need lots of ventilation, use an electric fan to speed it up.