A detailer with a hot water extractor might be a good bet also.
This will probably be my first car I'll run with rubber mats from the start. It is unreal how much dirt gets into fabric mats. This past summer I was too cheap to take ours to get properly cleaned so I took a powerwasher to em. Worked reasonably well actually.
But yeah, rubber mats FTW. My corworkers all use them. Dish soap and a brush, rinse, a little armorall style product, and you're in business.