I finally took the time to make my own red brick dust!! I will say that it is very hard work!
This is what I started off with. I actually have a few of these around the yard. The people who lived here before us used them as flower bed borders.
I hit the brick a few times with the hammer to break it into smaller, more manageable pieces. The piece on the top is the only piece I wound up using. I definitely recommend using a towel you don't mind getting messed up!! This is what happened after only a couple of hits!! Also, be sure to do it on smooth concrete. Where I was is some old sidewalk stones that are rough and the towel kept getting caught in it. When I moved to the smooth carport floor, I didn't have that problem.
After about 15 minutes or so, this is what I have now to work with:
I kept working for another 10-15 minutes on it and got most of the bigger chunks down to finer bits. It's not really smooth dust, but for me, it will serve it's purpose.