>>11143316
Good to know, never been near a vagina. Looks like the heavy butt plug route is the way to go.
This one is only 1.7-lbs, but it has two great features:
a) expands for better holding power
b) has a padlock. Instead of using the included padlock could use a heavier one.
http://www.amazon.com/Stainless-Steel-Lock-able-Anal-Bondage/dp/B00PQE3A3Y/