I've seen this before and rinsed with H2O and treated with sodium metabisulfate with good results. I've encountered a situation recently where the landlord had another CC'er (Chem Dry) out and they obviously didn't rinse properly as the carpet is pretty hard and has red stains like someone threw 5 gallon pails of Kool Aid everywhere. I HWE and treated with CTI Urine Stain remover restoring it back to normal...the landlord wants a written propasal on the situation. My question for all of you guys that are very good with chemistry: we know that there's too much soap left, but is there a certain chemical these guys use that causes this red staining and what is it? It sounds like a legal situation so I'm trying to get as much info as I can...I know most everyone here aren't Chem Dry guys but maybe someone is a former Chem Drier and can give some info on the stuff they use and why it left large red stains like this besides the obvious of no proper extraction, it seems to be a chemical thing as well