Don't want to question the value of your experience but I couldn't help noticing that your example and enraged_camel's examples all take place in the context of (mild) danger and risk. Employer-employee; employee-client; travel abroad.
Could it be that shared adversity is the key to bonding? Personal revealings would then follow gradually as a natural consequence. In this view the best way to make friends would be to go to high-school together, get stuck in an airport for 2 days, watch a horror movie, share a rock-climbing accident, etc. Mostly circumstances one doesn't have much control over, admittedly!
I think there's something to that. Most of my adult friendships with people that started in a professional setting were with people who I worked with on very stressful projects.
Lots of hours together, working very closely, gallows humor, and revealing personal details. There are about five or six people from a particularly stressful project that I talk to on no less than monthly basis, very personally catching up, and we're across 4 states and 5 cities.
Could it be that shared adversity is the key to bonding? Personal revealings would then follow gradually as a natural consequence. In this view the best way to make friends would be to go to high-school together, get stuck in an airport for 2 days, watch a horror movie, share a rock-climbing accident, etc. Mostly circumstances one doesn't have much control over, admittedly!