Airpods: how to forget all devices paired to AirPods

Hello,

I bought AirPods several weeks ago. Since then I have rented them to several friends to let them try it. I found out when you have several devices paired to it you can anytime connect to AirPods from any device they have already be connected to. So that means I can be listening to the music and any of my friend who has been paired with my AirPods before, can anytime switch to them, even at the time they are being used.

My question is: is there any possibility to forget all devices paired to AirPods? I know you can forget device directly from your iPhone, but can you forget devices from your AirPods, as well? I can't take all of their phones and one by one make them to forget device.