google "home-made carpet detergent", you can find a bunch of recipes, like
this one http://happymoneysaver.com/homemade-carpet-cleaning-solution/
here is mine:
1. 1-2 table-spoon (1 table-spoon=3 tea-spoon) Tide laundry detergent
2. 1 table-spoon white vinegar
3. 1 tea-spoon (=5 ml) oxiclean
4. 1 gallon of warm water
works nicely for me.
