But this would still not destroy Sauron

This is the same thing as throwing it int the Ocean, which was suggested at the Council of Elrond.  The Ring *would* eventually be found and returned to Sauron most or some other Power that would take his place.  The only hope would be to destroy it, which is what they did.

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Then Morgoth hurled aloft Grond, the Hammer of the Underworld, and swung it down like a bolt of thunder.  But Fingolfin sprang aside, and Grond rent a mighty pit in the earth, whence smoke and fire darted.  Many times Morgoth essayed to smite him, and each time Fingolfin leaped away, as a lightning shoots from under a dark cloud; and he wounded Morgoth with seven wounds, and seven times Morgoth gave a cry of anguish, whereat th hosts of Angband fell upon their faces in dismay, and cries echoed in the Northlands.

                       -- Of the Ruin of Beleriand and the Fall of Fingolfin
                          The Silmarillion