As all July posts appear to have been deleted, I am handily reminded of an earlier question I asked in June, to which I can now give an authoritative reply.
There are, indeed, Tesco Basic Thongs, available in packs of three, at a ludicrously low price. They are black, and look unutterably repellant. Despite this, I might have bought a set, had the only pack on show not been XXL.
I still can’t get over how dispiritingly craven England’s cricketing display was.