Yep. I get:

"This will remove explicitly defined permissions on all child objects and enable propagation of inheritable permissions to those child objects. Only inheritable permissions propagated from Rick Driscoll will take effect.

Do you wish to continue?"

So I click 'Yes'. But I feel like there's something else I have to do subsequently...?


EDIT: Ah, just went back to the 'Owner' tab for the folder 'Rick Driscoll' and noticed a check-box saying 'Replace owner on subcontainers and objects'. Ticked that, now it's taking its time doing something, I presume changing the ownership of the subfolders....