Crotch Rope

Here is a crotch rope that incorporates the hands. You can adjust for different body types as necessary. Oh, and in case you didn't figure it out on yor own when I mention that you can tie a knot in your rope and place it strategically before bringing it between the legs, I'm hinting that  you would place the knot on the clit or the perinium depending on the body type that you're working with. Here are some useful links in case you need a little help with the details:

Tracker's Column Theory
Midrope Column Tie
The Cow Hitch