I have been cleaning carpets and upholstery on and off since the mid 70's, but to this time I have avoided mattresses. For some reason I have been getting quite a few inquires of late and have lost some jobs for other work that I would have gotten if I did mattresses. So I am ready to take the plunge and want to know how mattresses differ from regular upholstery cleaning and special problems I might encounter or be able to avoid. What is the average dry time? Any help would be welcome.