Back when I was ambishous rebuilder,( /s)
I had a tool to run through the grooves to decoke the burnt oil seeping past the rings.
Long gone with the first sale of my shop tools.
This was something like it.https://www.ebay.com/itm/115253293709?
Blasting engine internals with something gritty in any way is asking/ begging for troubles.
Vapor blast if necessary, but it is not.