Chimney Saver pride themselves in being the leader in chimney protection. If you've got a problem, chimney saver has got the fix, with everything from water repellents, creosote removal, flashing repair, and more. Chimney Saver products have been around since the mid-'80s, and people have put their trust in this company to keep their chimneys leak free ever since.
I have a limestone fireplace that is quite old with burn marks on the limestone. Will your product work on this? The grout isn't in too good of shape and I'm afraid your product may pull some of it off. Will it?
The masonry cleaner product will work for your application. I would recommend spot testing it before using on the entire brick facing.