I've been doing some brain storming on this issue for something to threaten my slave about.
So far the worst thing I can come up with is grinding up Habanero peppers and using it as a vaginal lubricant.
I'm not all that sure if this would even be safe, and I know from experience that when...
Yes, It is very possible, and I've seen numerous videos that have featured it.
Just to warn you though, there was a case I saw where a girls tits died because of how tight the rope had to be while doing this.