I believe that hydrochloride etching is whats used on glass, I posted this in the "how do you make your mark" last week as an alternative to everyones branding and got no bites..... I am still curious to see how it will work.
One problem, I doubt that machine has the tollerance capability to create an intricate etch sized image...
I have problems making images that small with my industrial cutter...
It wouldnt hurt to give it a whirl, but the acid kit was 75$ ish and I already have my hands tied in 10 other projects LOL