Easy grout cleaner

I clean for a 135 year old restaurant/bar/tavern, the grouts in the bar are horrible (pic 1) cuz no one has cleaned them before. I used bleach, degreaser and PinAlen (an awesome degreaser/multipurpose cleaner) and a brush atached to my drill. pic 2 showed the little bit I've done so far with too much elbow grease and time. Does anyone know of a much easier way to clean tthem?
q easy grout cleaner
q easy grout cleaner
  7 answers