Review on StoneTech Soap Scum Remover: Effective Cleaner for Natural Stone - 24oz Spray Bottle (2 Quart Pack) by Stephanie Rivera

I have found this product to be excellent at removing scum and will not damage my marble or limestone. It's a pretty mild cleaner, so you'll still need some elbow wax and one of those plastic cleaning sponges to really get the job done. A toothbrush is also needed to get into the cracks. Pretty expensive for what it is. I don't know what's in it, but it smells like a common ammonia-based household cleaner. They're not recommended for limestone, so maybe it's just more diluted or has a special ingredient in it or something. Either way it seems to be working. It might have been worth it if you had neglected the situation for a while, but I would try to find another solution for regular cleaning.