Amazon also sells a $50 grappling hook that actually is recommended for climbing and it's not rated much higher than this:

https://www.amazon.com/TI-EDC-handmade-Carabiner-Grappling-Climbing/dp/B00DWUU1KY

Personally, I use one of these

It serves a dual purpose of weeding out the girls who won't go on an adventure to "obtain a view" ;)