How soft soft?
I did a fair bit of blasting of steel and aluminum bike parts, at one time in my past. Glass bead was the gold standard for pulling up a nice finish or stripping paint, etc. without doing too much surface change.
Glass bead fed into a pressure washer cleaned up cylinder heads to near factory fresh looking, though it was a production to do, requiring a fair size, tarped in area to recover the bead, if you did.
But glass bead at low pressures will blend over the sharp edges of any scratches or pitting, without leaving sharp deeper pits, which are more what you get out of the AlOx or crushed glass particles.
It's really nice to have access to a couple types of medial and see what gives you the look you want.
Cheers
Trev