All I can say is I wish I had found this product years ago.
One of my biggest pet peeves was how dirty the grout on my counter top was, and anything and everything I tried never seemed to work. I was at the stage where I was considering letting a professional regrout it (this promised to be an expensive venture).
Thankfully I took a good friends advice and gave my counters one last chance to brighten up before I brought in the big guns and boy am I glad I did - my counters sparkle now. Once again I love them and once again I see the point in consistently wiping them down.
The Clorox Bleach Pen is to put it mildly a miracle worker and the effort I had to put in was minimal at best. Admittedly it was a tedious task but seeing immediate results kept me going, nothing frustrates me more than cleaning with zero to show for it.
The prodcedure in and of itself is simple: take the bleach pen and squeeze it over the dirty grout to apply a line of the bleach, let the solution set for about 5 to 10 minutes and then simply use a toothbrush to lightly scrub the grout (no serious elbow grease needed), wipe down and to finish off spray with windex to remove any gritty residue.
I know a lot of people would worry that the smell might be overpowering but its not, it's what I can best describe as a "fresh, clean" smell.
This procedure will also work on ceramic floor grout, but truth be told this is a much bigger task and one I haven't quite found the energy for yet, but I know when I do I already have my solution. The only improvement I might make to this product would be to put it in a spray bottle for wider areas (the pen will always be my go to for the counters).
I guess it's pretty obvious by now that I highly recommend this product for the cleaning and upkeep of your grout. Buy it, use it, love it!