When Harry confronts the basilisk, he is wearing his Sneakers, but he manages to break the runes on the soles and we find out just how spectacularly the spells on them fail when that happens. Harry’s throwing knives are ineffective against the basilisk, so he draws the Sword of Gryffindor from the hat and uses it with a knife in the off hand. When he kills the basilisk, he sees the fang coming and slices through it with the knife, causing the knife to imbibe basilisk venom. He stabs the diary with the knife to destroy it.