This is a quick video showing a carpet stain removal performed by Chem-Dry of Tampa FL. There are several layers to this stain. Some are biological and some are chemical. The stain started pet accident created by a dog that got sick and soiled the carpet. That's the biological part of the stain. The home owner made an effort to clean the spot and ultimately used a fabric softener to cover up the associated odors from the stain.
The carpet stain removal process starts by sanitizing the carpet to kill the micro organisms that there. Making the carpet healthy is the priority in dealing biologically based stains. The heat and cleaning solutions do not kill micro organisms. They have to be chemically neutralized and then removed with the cleaning. After the sanitizer is applied to the carpet it has to dwell long enough to kill the bacteria and that takes about 20 minutes.
The next step is to apply the stain removing solution that breaks down the soils and emulsifies them so they can be more easily removed. In the end it is going to take some aggressive agitation to break it all down to be removed. The video is partially paused so more stain remover could be worked in to the carpet and cleaned again. This takes some dwell time and there was no point and letting the video run the entire time.
The end result of the cleaning was a safe clean carpet with no odors.