Use Mr. Clean in a Rug Doctor carpet shampooer. Cheaper than the brand name solution. $3 v/s $20. My carpets are off white. The color in this solution will NOT stain your carpet. See the treated side of the cola stain? I used Mr. Clean 'Gain' scented. My whole house smells like Gain dryers sheets! Use 1/2 cup of Mr. Clean per 2 gallons of hot water.
Homemade carpet solution for a Rug Doctor. Mix hot water with 1 T Dawn, 1/2 cup Oxyclean stain spray, 1/2 cup of Borax. Pull the shampooer backwards very slowly for results like this. This is the spring after our wood furnace blew soot everywhere.