To get the smoke smell out of foam cushions remove any coverings if possible and then sprinkle the foam cushion with some baking soda and let it sit for a few hours.
Then mix some vinegar with some water and then spray the foam cushions with the vinegar and water solution and let it sit for awhile.
Then use an upholstery cleaning machine to go over the cushions with another mixture of vinegar in the upholstery cleaner or mix some odor neutralizer in with the water in the upholster cleaner.
Then go over the cushions with the upholstery cleaning machine to deep clean the foam cushions and remove the baking soda and other residue.
You can also use some store bought upholstery cleaning products to give the foam cushions a good cleaning but usually vinegar and water and even the baking soda works great as a natural cleaner to remove smoke smell.