To me, practise should include being aware of the risks and problems of what you practise. Barbie does not struggle to get free. And her limbs don't go numb if you tie something to tight...
Cheers
FF
There are 10 kind of people in the world. Those who understand binary numeral system, and those who don't.
If you don't have a "live victim" as Fesselfan put it, just tie your own ankles, or other body parts to something. That way you can struggle and see if it's really tight enough to hold you, or if it will cut off your circulation.