The best way to protect your sofa with ease is to wrap the sofa seat cushions in a layer or sheet on a bed roll.
Or you can also use washable and removable sofa cushion covers or plastic wrap over the sofa seat cushions.
Using washable sofa cushion slipcovers can help you keep your sofa clean and you can remove the sofa cushion slipcovers and wash them in the washing machine to make it easy to clean your sofa.
Some couches also come made with removable cushion covers which can be removed and easily washed in the washing machine although it's also important to note that not all removable sofa cushion covers are washable in the machine.
Some types of sofa cushion covers will have to be washed by hand.
To clean non removable sofa cushion covers you should vacuum them regularly and spot-clean them with a fabric-safe cleaner or mild detergent.
For deep cleaning, a steam cleaner or upholstery cleaner works well to sanitize and refresh the fabric without soaking it.