Use a soft-bristled brush to work the solvent into really dirty areas. Hold it at least 6in (15cm) away and move it around steadily so it doesnt damage the cushion. Being the epicenter of every house, couches take a beating every day. How to Clean a Couch Like a Pro. google_ad_width = 336; This image is not<\/b> licensed under the Creative Commons license applied to text content and some other images posted to the wikiHow website. If you can't remove the cushion, vacuum the mildew-stained sofa with the machine's nozzle attachment. Develop the tech skills you need for work and life.