pick and choose the easy ones. If you put the word out that you offer this service you'll have every scum bag and their 30 year old rotten grout, molded through and through, caked up butt wads, loose tile, stalagmite pos calling wasting your time.
You'll need box and straight razors, pics, dental tools, every fiber pad color, Cobbs acid, Magi Als Glass and Metal Magic, Stone Scrub form Stone Pro, 0000 steel wool, HEPc shots, knee pads, enhancers, caulking gun and white, almond and clean silicone, re grouting skills, a radio or Ipod and the balls to tell them you aint stepping in for less than $300.