I work for Fiber-Seal, which has been in business since 1971. We, too, seem pricey at first glance, but offer a 12-month service contract to remove any spots if you choose to protect your carpets. We apply a sprayed-on product that reduces the absorbency rate of the fibers, so if your dog piddles or your kids drop their pizza on the floor, you have time to blot up the mess. Your next step is to call us, then we'll schedule a spot call and come out for NO extra charge. Of course, if the entire neighborhood comes over and drops pizza everywhere, then it would be a full clean job, but at that point I would reconsider ever serving pizza to those neighbors! :-)
Seriously, though, when we clean carpets (or furniture, since we do that, too), you know up front what the cost is. I would come out to do the estimate and the techs (who have all been with us for over 7 years) concentrate on getting rid of the stains. We do warm-water extraction and only on rare occasions do we use the encapsulating method that the previous poster described. All of our products are tested thoroughly for environmental safety, as they have to conform to CA standards, too, since we have offices there as well.
Lots of information for you, but I am really picky as to what comes into my house, especially since I'm a cancer survivor of 7 years. If I didn't believe in this company, I wouldn't be with them. Please call me if you would like me to give you an estimate. Thanks, and good luck with your search!
B. Biehl
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www.FiberSeal.com