This video on how to perform a DIY upholstery cleaning encourages you to remove your cushion covers and run them through the washing machine. As a professional upholstery cleaner I don't recommend washing your cushion covers in the washing machine. Upholstery coverings are not designed to be run through the washing machine. The video also recommend using blue dish soap and water to spot clean your upholstered furniture. Again, with my professional experience I would not recommend using these tips to clean your upholstery.
This advice might sound self serving since I get paid to clean upholstery, but upholstery covering can be sensitive materials and can be damaged by the actions seen in this video. As a professional upholstery cleaner in Tampa FL I run into damaged upholstery on a daily basis. Everything from missing buttons and broken zippers to bleached fabric and stained material coverings.
In the video the upholstered sofa is a durable synthetic covering that can take a lot of abuse. It's polyester based fabric can be cleaned aggressively. If this were done with a softer cotton or poly blend it could be permanently damaged. Your washing machine is an aggressive form of cleaning that can damage zippers and split seams on upholstered furniture. Not to mention color damage by harsh detergents and bleaches.
I would also advise to using dish washing detergent in fabrics. The blue due can stain the fabric and the soap can leave sticky residues behind because it's not rinsed out.
Most professional upholstery cleanings cost around $100.00 and yield better results.