There are several products on the market designed to clean faux stone fireplace, but most of these contain chemicals. If you want to avoid chemical cleaners, and avoid buying a cleaner specifically for the job, then use the following products, which you may have in your home already. First, to clean the stone, use shaving foam, as this is basically just regular soap but much easier to clean off. You may notice that this may not have worked very effectively on the grouting. Moving onto step 2. Using a toothbrush that you do not plan on using again, dip it in vinegar and scrub the grouting. Although time consuming, this is very effective.