Glass can be etched with hydrofluoric acid (HF), not hydrochloric. While both acids are very dangerous, hydrofluoric is EXTREMELY corrosive to organic matter such as human flesh and will cause horrid burns that may never heal. I had to use HF a few times in my career since it was the only way to etch some very inert plastics, and I was not happy about having to do the work.

Etching creams that contain sulfuric acid, sodium bifluoride, and ammonium bifluoride are sold and are "apparently safer". I would not go near this compound either, even with gloves that are rated for acids and a lot of other protective equipment. I'm sure glass etching can be done safely once the proper equipment is set up, but this has to be done with a lot of thoughtful preparation.

Fred, it must have been rather "thrilling" to see someone doing acid etching. Wondering why sand-blasting or tumbling wasn't used instead...