Asking users to "try waving the cursor around a bit" should now join the list of last-resort suggestions kept up the sleeves of flummoxed support staff and people giving advice to non-techie friends and relatives.
I've found that this works on my tablet too.
Those instructions would have to be rather vaguer, though, on a tablet. It basically amounts to stabbing the cookie pop-up in random places until I hit the hidden "I AGREE" button underneath. Would look very odd if I were doing it in public.
I'm not sure whether to be frustrated or consoled by the fact that even though I have to go through this process, none of the third-party cookies will ever arrive on my browser anyway.