Today  I went to a carpet cleaning job in which the homeowner had cleaned the own carpets in the past.  They had the best intentions when they cleaned, but left a lot of soapy residue behind and it cost them as much money to rent the machine and do it themselves as it would to pay a professional.  When I arrived I noticed the carpets were dirtier than normal and I applied a defoamer.  The defoamer strips the soap from the carpets and removes the soapy residue.  We do not have any additional charges for this service and they were a pleased customer.