It's 3 in the morning and you just finish the tile job and you cut it a little short on some of the clean up and making sure the grout lines are cleaned out completely... I'm sure a few of you have had to remove dried excess thinset in grout lines or wherever like I have had to in the past. I've learned the hard way that it's much easier to just clean everything up no matter how tired you are.
But I've learned the best way to remove excess in grout lines and on the sides of tiles. I've tried mild tile cleaner and acid. Both don't work that great. I've tried the triangle shaped grout scraper and the diamond blade grout saws.. Again, not that great and they can scratch tiles. The best method I've found is a Dremel with a skinny pointed grinding stone (I've used the orangeish one, haven't tried the green). It doesn't seem to damage the tile very easily either, unlike a slipping diamond blade..