I have done a few sets too and all I use is an air hammer with an extension I made. If you do it carefully you don't leave any external marks and the inside looks clean too. This is what I use. I use just the angled chisel with the vein on top for the first baffle then I use the extension I made as needed.
I learned all I need to know about life by killing smart people and eating their brains. Eat right ,Exercise ,Stay fit, Die Anyway!
