I think it would work ... in part... a thief isn't going to be looking at bits of wire near the bike... they wouldn't notice it - they are just looking at the lock and checking they aren't observed. As to whether the wire would work - I expect it would break but it would probably check their speed and might then get tangled up in the mech causing an accident.
I've thought of similar things for locking the bikes up when we are away for a couple of weeks. I go for the multiple lock every bike to each other and the lawn mower, so they don't fit through the shed door.
Didn't any of you ever use black thread strung around to trip people up when you were a kid