Well it was a revived 2012 post…
Part of the process is to etch the surface. However, it will show imperfections. Shot blasting might be a good fit, but you might want to run a sample first. Most everything I deal with that’s anodized has a brushed finish.
Also, don’t bright dip it. It won’t last outside.
Do you know the spec on the abrasive making it?
Neighborhood of a #4 finish in flat sheet finishing. I believe it ends with a 220 grit paper.
thanks for the fact Rony! 
I’m now craving some General Tso Chicken.