Abrasive blasting would be too aggressive. I use to sand carve glass (actually used aluminum oxide at low pressure but high feed) and this would almost melt anything plastic that it touched and the surface would look like a rasp had been over it. So I believe it would look worse than before you started.
I have played a little with ABS prints and a vibratory tumbler and ceramic triangle with a little soapy water. It takes a long time but does smooth the surface a bit and the end surface is more matt than glossy looking. Though a polishing stage might make it glossy again.
