Upholstery cleaning disaster- advise
We bought a beautiful dining table and 6 chairs from Craigs list. The chairs have thick upholstered seats. The fabric is thick, woven, and off white. The seats had some soil on them. I used the upholstery attachment on my Hoover upright steam cleaner and ProForce Carpet and Upholstery Cleaner from Sam's club to go over each seat. They looked great, I went to bed. When I woke up each seat had brown almost streak like discoloration on it only at the corners and along their front edges. Some are worse than others. I re cleaned just one using a soft brush and the same cleaning solution. After an hour, I removed all the brown discoloration. After a half hour or so, the brown re appeared. To me, it looks worse than the first time the brown appeared. I wish I could show a picture. It is hard to describe. Picture an off white dining chair seat that someone took a larger paint brush that had been cleaned but still had a slight bit of dark brown paint in it and gently brushed it over the front edge and corners of the fabric feathering it out as they brushed over the fabric. The entire top of the fabric seat fine. Before I started the first cleaning I looked for a fabric content tag or any tag with cleaning instructions. The only tag says 100% Polyurethane Foam. It also gives the company name who made the dining set which did not come up on a google search.
Any suggestions would be so much appreciated.