Faraday cage - suppressing stray EM fields

Many have been to the boston museum of science and
seen the faraday cage at work in conjunction with their
van der graff accelerator. Guy sits in a big cage - creates
huge lightning bolts, protects himself and audience using
Faraday's law which requires field inside enclosing
conductor to go to zero.

My question is: Wouldn't braided ground wrapped around
power cords, speaker cables, interconnect provide ideal
isolation of these components from one another?

If this is already a part of interconnect or speaker cable design, then why should coiling speaker cable in a pile
matter? Would expect leakage to be confined to termination
points of cable.

Is this principle incorporated into highend power cord design?