I agree with Gugi that acid is an extremly bad idea and very dangerous made even worse by heating it!!!!!!!!!:chop::chop::chop:
I also agree with Gugi about leaving the pitting where it is due to it's depth. If youregrind the blade it will change the shaving characteristics a lot. I prefer to experience the blades\shaves in as original a configuration as I can based on how I received it. Most every blade I have that was used was in use longer that my experience with straights and I would like to shave with it in that configuration with few exceptions, like frowns. If the pitting bothers you get some MAAS and a tooth brush and have at the pits. It will not remove the pits but will remove the black in the pits. DO NOT USE ACID!! :gl: