Out of complete stupidity I layed a dark grey slate floor over a year ago
and grouted it with white grout. Being in a kitchen its quickly discoloured
and now looks bloody awful.
I want to remove all the old grout and redo it with grey grout which won`t
show up all the crap. What is the best way of doing this given that the
grout lines are between 0.5 and 1cm ? - its also a large area (approx 20m2)
so its going to be a back breaking job :-(

Steve