Hardening gold-filled wire?

Orchidians,

Another lurker comes to the fore due to technical challenges! I’m a
jewelry designer and lapidarist, and have just taken up
metalsmithing. My instructor wasn’t sure of the answer to this
question (and it was not in the archives here):

A friend wants an inexpensive neckwire for several large beads –
can I make one from gold-filled wire (half-hard) and harden the
necklace further when it’s properly sized? A suggestion was made to
put the wire in a vise and use my hand drill to twist it slightly to
harden it. Or would I heat it in a kiln?

Thanks to all with suggestions.

Roseann Hanson
Desert Rose Design Studio
Tucson, AZ