Q: Jason, have you ever had to clean the black soot marks off the outside of your fireplace hearth? What cleaner do you recommend? – TY
A: There are quite a few products on the market to do this. With all of them, you should be using rubber gloves and safety goggles.
My favorite for stone is a product by Simple Green. You apply it and lather it in with scrub Brillo pads and stiff brushes. Be careful in all situations not to overwork the grout and work bottom to top to avoid streaks.
For brick surfaces, you can by Aquamix from most big box home retailers. Careful with this stuff as it has a high alkali content.
In either case, it takes time and elbow work. Good luck TY!