ugh I so need to do this, I should of sealed the grout when we moved in but of course I put it off, And there is alot of it, Starts at front door goes right thru to the kitchen, is in the laundry room and the powder room, going to take me many weekends to clean it. I am thinking of making this my winter project and then you can be sure I will be coating it afterwards. I really think this is something that the builder should do as soon as the ceramic is finished. I am so mad at myself! I had white grout years ago and I use to clean it with a toothbrush and diluted javex! Not sure what I am going to use this time