Quote
Dry Conditions: Current = Volts/Ohms = 120/100,000 = 1mA
a barely perceptible level of current

Wet conditions: Current = Volts/Ohms = 120/1,000 = 120mA
sufficient current to cause ventricular fibrillation

This is from one of Joe's suggested links.
Body resistance is going to vary according to conditions.
So we have under dry conditions 100,000 ohms down to 1000 ohms thats quite a variation.
As far as difibrillation they rule is to start out at 200 Joules and work up, a child of course they start at 50.
As I said seems to be some misinformation out there.
Mark