I thought I'd share my somewhat limited experience of blasting.
I bought my Porsche Design Chrono from a seller in the US, in the full knowledge that it has been blasted of its PVD, and that it had suffered as a result (the price did reflect this). Here is one of the seller's photos to show the damage to crown and pushers.

The same is true of the caseback, seen also below (you can just make out the PD logo on its side in the centre, but the rest is a bit too hard to discern)

I am working on the caseback (see later post) but the pushers needed replacement, so I went to Rocco Manfredi, the local watch guy, and asked him to get me a pair, which he did. Of course they were polished steel, and not a match in the slightest, so I set about finding how to blast them. Local to Bristol in Avonmouth there is a specialist whom I spoke to, and he informed me that blasting can take all sorts of forms, using all sorts of media (sand, sharp and round, walnut shells, beads etc), at all sorts of pressure (in the air blast). You can even use all sorts of different nozzle sizes to do different sizes of work. So I took the pushers down there, located onto a piece of wood suing a small drilled hole, and he set about blasting the pushers to obtain the matt finish I required. The two crowns took a total of 2 minutes, including an inspection after one was done. Here is the finished product.

A good match, I reckon, and you might struggle to think that they are not the original pushers (even if the damage to the crown is still evident).

For me, the point is that blasting can be as rough