Can transcranial stimulation be simulated by sensory stimulation?

There is much interest at the moment in non-invasive forms of brain stimulation. The latest report comes from the BBC, 17th May, 2013:

"Transcranial random noise stimulation (TRNS) involves applying random electrical noise to targeted areas of the brain by placing electrodes on the surface of the scalp.

It is a relatively new method of brain stimulation which is painless and non-invasive."

"It could help those suffering with neurodegenerative illness ..."

See: http://www.bbc.co.uk/news/health-22556735

A description of TRNS is given in:

"Evaluating Aftereffects of Short-Duration Transcranial Random Noise Stimulation on Cortical Excitability"

Leila Chaieb, Walter Paulus, and Andrea Antal
Neural Plasticity, Volume 2011 (2011), Article ID 105927
http://www.hindawi.com/journals/np/2011/105927/

The transcranial approaches apply small electrical currents or magnetic fields to the head.

This may be possible to DIY - but, clearly it carries some risk.

I wonder whether a simpler, and possibly safer, approach is to involve the sensory system to "naturally" generate electrical currents in the brain. See the following thread:

http://neurotalk.psychcentral.com/thread172359.html

Or, perhaps simpler still, is to listen to your favorite music.

John