I have used it
And it did freshen the dishwasher that was in my house when I bought it. Of course I threw that machine in the garage after three weeks for other issues.
I don't have hard water crust issues so I can't say how it works on that, but I have good results with 1/2 cup of LCB and the short cycle. I also leave the door ajar after use. Sometimes odors occur when I don't have a full load for a few days. The rinse option is helpful for those problems. My worst issue is stinky formula smells--bleach.