I received my Chargon a week ago but didn't get around to trying it out until last night.
Yah, it is a simple tool and priced much higher than it "should" be, but it is worth the $20 I paid for it. It cleaned my RCP grates up much better than any brush or other tool I have used. I don't know if it would work as well for smaller diameter rod grates, but for RCP 9mm bars, it works soooo well.
That being said, it is a very simple tool that could easily be fabricated at home. Years ago, there is no way I would have paid $20 for it and I would have gotten a hold of a piece of 1" flat SS stock and made my own. But, as I get along in age and ambition, I am very happy to pay the $20 for a tool that do such a good job and last MUCH longer than a brush.