And here i was just thinking electricians were either lazy or constantly playing with themselves. Seriously i never heard that rule and i have worked and socialized with several electricians for years. The best way to stop an electric shock going through your heart is to make damn sure the item you are working on is disconected from the power supply.
A competent technician doesn't just slap something together, back up and cross their fingers, they check circuits while operating which requires power. Also, many faults cannot be found without probing a (semi-) live circuit.
Granted this is more often in the realm of electronics and repair work than general electrician work, and some forethought and preparedness would suggest that a current limited supply is a good idea - a homebrew way of achieving that is to feed the hot AC power lead through an incandescent light bulb. Even so that is more for a basic circuit protection, enough current will flow through the lightbulb to stop the heart.
As for the odd question about electrocution by various wire types it does not matter. The resistance of the human body is far larger than the resistance difference from different types of wire... both are metals chosen to be reasonably efficient at transmitting power and their resistance difference is trivial when talking about the few mA current needed to electrocute, but if you want it to be gruesome, dial back the current so it takes days or consider death by spoon.
http://www.youtube.com/watch?v=9VDvgL58h_Y