Regarding Steam cleaning and Scotchgard and similar coatings: It stands to reason that such coatings that resist soiling of fabric would indeed degrade and be ruined by steam, since such coatings are forms of plastic (polymers) that are quite sensitive to high heat. When a plastic is subjected to high heat (the effective exact temperature differing with each type of plastic and the surface it is adhered to), the long chains of polymers separate into monomers and resins which is seen in rigid plastics as first cracks, then crumbles, then dust, sometimes with an 'oily' residue of their 'plasticizers' on nearby surfaces. Further, when a plastic degrades it "outgasses" a number of not-so-healthy chemicals that we are forced to breathe! Even in the application of Scotchgard, for example, there are an undisclosed number of chemicals voided into one's atmosphere in addition to its stated propellant chemicals if an aerosol.
How damaging are they to you and your workers and patrons? That subject has been debated for some years now, and while it is highly unlikely that a patron would sue for the presence of such chemicals, you may want to be concerned about the long term effects upon you and anyone else among those treated areas for long periods of time.
Some of you may remember that years ago 3-M company (maker of Scotchgard), discontinued the making of it "for environmental reasons" but others claimed it was their fear of litigation resulting from possible chemical poisoning that encouraged that self-preservation move. Well, for what it's worth, here is their 'official' position on the old Scotchgard versus the new:
http://solutions.3m.com/wps/portal/3M/en_US/Scotchgard/Home/Resources/Environmental/
If this link does not work because it is 'folded', merely paste it in sequence into your address box of your browser. Should we agree with all of their contensions?
Sooo, it may be less hazardous in the long run to rely upon standard steam cleaning, rather than these Teflon-like chemicals which are well known to kill any birds in your home if voided into the air by an overheated Teflon coated cookware, which sometimes has warnings to this effect right on their labels. Is it as the famous DuPont slogan says: "A Better World Through Chemistry" -- or just a more profitable world for a few in the short term???!!!