
Based on the provided search results, which do not contain specific information on this topic, the following guidance is based on general professional cleaning knowledge.
Cleaning a sofa with a steam cleaner that lacks an upholstery attachment requires significant caution. The standard nozzles are designed for hard surfaces and can release steam that is too hot and concentrated for fabric, potentially causing water damage, discoloration, or shrinkage. The primary function of an upholstery attachment is to disperse steam more gently and broadly.
If you must proceed without the proper tool, a widely used workaround is the towel method. First, vacuum your sofa thoroughly to remove any loose dirt and debris. Before starting, it is crucial to check the sofa's cleaning code (often found on the tag) and to test the steam on a small, inconspicuous area to ensure the fabric is not damaged.
To attempt the cleaning, wrap a clean, absorbent microfiber cloth securely around the end of the steamer's nozzle. This cloth will act as a buffer, helping to diffuse the steam and prevent direct, harsh contact with the upholstery. It will also help lift and absorb dirt as you clean. Work in small, methodical sections, applying the steam in short bursts and constantly moving the nozzle. Do not let the steamer rest in one spot, as this will oversaturate the fabric.
Immediately after steaming a section, use a separate clean, dry cloth to blot the area and absorb excess moisture. After you are finished, ensure the sofa is in a well-ventilated area, using fans or open windows to speed up the drying process and prevent any mildew from forming. While this technique can work, obtaining the correct attachment is always the safest and most effective method for cleaning upholstery.


