I'm sure your right with a few of the aspects of using different methods, as with any method, there is always an element of risk involved and using correct PPE's and as pointed out in the link I put up, proper enclosed work area etc there should be minimal risk of taking skin of hands, eye damage avoided by wearing correct eye protection and of course masking up, as with any potential risk. I have not tried this method as yet, but considering it is rather cost effective, my suggestion would be to try it out on sample pieces. Not sure about the wear and tear side of the method, but like anything etched, if you rub it enough would likely change its appearance. You seem to be iron clad on using acids and electrical methods, where there is certainly areas of risk involved, lazer is exspensive and if setup well and good, not a path I would choose to have to spend large amounts of money for unless I was going into production for the use of.