Alternate "Hiding the Ring" strategies

[Raynor]

Ungoliant, though, was not an earthly force.

By what criteria?
Even if she is a maia, she is too bound to her bodily form and her needs (not to mention that in BoLT, she is said to have bred from mist and darkness, after the overthrowing of the lamps). And being a maia (and thus not an "earthly force"?) is not much of a measure of strength, seeing how elves made quick deal of some balrogs, Gothmog included (balrogs which almost finnished off Ungoliant ).