I just tried this and it works and my carpet smells fresh and clean! So much cheaper than store bought stuff! The Retro-Modern Mom: Homemade Carpet Shampoo (Borax washing soap instead of the laundry detergent.
How to Make Homemade Carpet Shampoo or Rug Cleaner
DIY Carpet cleaner for a machine. 1 gallon hot water cup peroxide 4 Tbsp white vinegar 4 Tbsp Dawn dish soap, cap fabric softener (I used Downey) Stir slowly then add to machine as directed by manufacture. (I used a Bissell ProHeat Machine) Works
Easy Homemade Carpet Cleaning Solution for Tablespoons Liquid Tide Laundry Detergent cup Awesome cleaner (dollar store brand) 1 scoop Oxyclean (I used generic dollar store brand) 1 teaspoon Downy Fabric Softener (optional) Hot Water, one gallon