I used to work for Steve back in the 80’s. We used a 2 machine process back then too. Using a shampooer on the carpet started the cleaning process and dissolving stains, then we rinsed the carpet with clear water, so no residue was left. The carpets would dry soft, with no shampoo residue left. Steve is one of few business owners that still practices this method. Same method for furniture, but scrubbed by hand. We usually had 100% satisfaction.