Hi,

Last night I tried to clean fireplace but had little luck. I mixed muriatic
acid with water 1:10 and sprayed brick inside fireplace, then waited about
20-30min and then brushed it with metallic brush. In same places I was able
to brush off black stuff easily, but where wall was really black this did
not help a bit.I read that muriatic acid is very good for this type of
cleanning, but probably I did something wrong.

Anyone else could point me what else helps in cleanning this?

Thanks