We used that process to hone .30 barrels for machine guns. It was messy, time consuming, and left a questionable finish. Any flaws in the bore after drilling would wallow out creating a larger diameter at the point of the flaw. It was also known to widen the entry and exit points, leaving the middle tight and the rest loose.
The company got away from using that process and bought a couple million dollar stick honing machine that could be controlled more precisely.
To do it yourself ain't worth the effort. The equipment has to be able to reach pressures to push the media through and also create a back pressure to keep it from just running through the bore. If I remember correctly, the machine we used ran between 1k to 1.8k psi. The media was a mix of moly, wd40, and silica that the engineers came up with. Took about 45 mins to run the cycle and a couple hours to clean up the mess. Damn thing had somewhere around an 18% scrap rate. That adds up quick.
