Good old Tumblr took it down but I posted it again on my bdsmlr:
https://edgingspace.bdsmlr.com/post/32558813
Also if you search that for crotch ropes it has all kinds of ideas!
https://edgingspace.bdsmlr.com/search/crotch%20rope
Oh and bdsmlr have an app now!!! So you can use it without it showing up in your search history. It’s still in beta but working well.