Well I misread that whole thread!

The original post said "I could hang it off a hook and fasten it to the
window sill".

Which I took to mean; "I could hang IT off a hook 'AND' also fasten IT to
the window sill". 'IT' being the pot? Right?

So, some of the weight would be hanging from the hook and some of the
weight, IT (the pot), being fastened to the window sill, would be taken by
the window sill!

So I started thinking about the diameter and weight of the pot and the
leverage due gravity on a cleat fastened sideways to the window sill....!
But;

It wasn't that complicated at all! Although the thought of a multi pound pot
swinging up against the window sill on a windy night?

Visions of someone out there in their pajamas trying to unhook that pot in
the pouring rain .................! Maybe an anchor or two, laterally would
be a good idea?

BTW 'pot' did refer to the container not the contents? :-)