Conacted two metal firms that do metal polishing and deburring. Another doesn't do it anymore (apparently a lot of manufacturing has been relocated on low cost countries to lower manufacturing quality) and another does manually. Both knew what was after but could offer only synpathy.
I made few enquiries about crushed glass, for some reason very fine as a blasting media is really easy to get, but real granules are unoptainable, next step is decoration size.
How ever local hardware store had "foam glas" for insulation, I really don't know what that is in English 50 litre bad weights about 20 kg and costs 14 Euros. Since it is actually a usefull medium temp insulation material it probably has more use as a . insulation.
It is pretty friable and floats atop of water. I put some parts for about 40-60 minutes cycle to it, checkking every 10 minutes and a tool steel shank come out really nice. Other parts were interesting. This media knoks off finest burr, and matts the surface if it of decent quality, but really strugles with pitting/rust etc. Good news it that matte-finish ir really shallow, hardly any dimenssional change, dis nothing to internal holes or threads.
Looks consumbale, the media rounded off fast and a 30% of it was reduced to sludge. I washed them to start with. Sludge/dust is easily rinsed off, it is really fine and hard so see how it would have any enviromental hazard.
It would be pretty good if it were a whole lot harder/heavier. Maybe good for plastic or other soft material.
I have a problem with "stone", think there is danger of leaving hard particles behind. But might need to try that one next.
Pekka