Bulk clear custom properties

Similar to how we can "clear" or "reset" transforms, e.g. using ⎇ Alt G or the Clear Transforms menu:

It would be handy if we also had operators to clear custom properties back to their default values. Righ now we have to hover the properties and hit ⟵ Backspace , which is functional but poorly scales up.

Specifically when animating armatures, it would be useful to have an operator to clear the custom properties of either the selected bones or the whole armature. Because we also have situations where thanks to custom GUI (e.g. from Rigify) we have access to custom properties by selecting bones that do not actually wear that property (e.g. Rigify shows a limb's properties as soon as we select any of that limb's FK/IK controllers).

Mockup:

Or perhaps we could put those operators in the "Clear Transform" menu, and rename that menu to "Clear".

In the meantime, i made an addon for it:

Reset Custom Properties — Blender Extensions