I have watched Doug Ledger (a very deft British glass lampworker) winding horrible soda glass which is much less flexible than Moretti around copper wire to make beads, then he just puts one end of the wire in a vice and pulls which stretches and thins the copper and then the bead slides off, leaving a thin reddish residue of copper oxidisation or whatever it is! I havent been able to do it though.
Henry Spooner used to use galvanised garden wire and etch it out afterwards with acid. Not all metal pickling acids attack glass, his remained shiny. Remember acid such as Nitric is often stored and used in glass bottles and vessels and they dont dissolve.

In India the mandrel release probably has a lot of chalk powder in it, The Japanese and Chinese beads have a slightly pinker and finer version, and some other glass beadmakers I know work with a graphite and beeswax mix.

Stefany