Did Harry use magic in any (or at least significant) way in the Chamber of Secrets?

Question

Would Harry have won (achieved the same exact outcome) in the Chamber of Secrets if he somehow would have been turned into a Squib for the duration?

I'm trying to remember the whole end of CoS, I am failing to remember a single spell or magical thing Harry did during the entire set of events once he had entered the Chamber.

Did Harry use magic in any (or at least significant) way in the Chamber of Secrets? (to be more specific, after the rock fall caused by misfired Memory charm, and until Fawkes flew the whole group up to the castle).

Answer 1

Synopsis: Nope; other than speaking the language of snakes, he did no magic. And speaking the snake's tongue may not even count.

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He did use Parseltongue to open the door, but I'm not sure if that counts as using magic.

Harry approached, his throat very dry. There was no need to pretend these stone snakes were real; their eyes looked strangely alive. He could guess what he had to do. He cleared his throat, and the emerald eyes seemed to flicker.

“Open,” said Harry, in a low, faint hiss.

The serpents parted as the wall cracked open, the halves slid smoothly out of sight, and Harry, shaking from head to foot, walked inside.

After that, he never had a chance to cast spells; the incarnation of Tom Riddle picked up Harry's wand right after he came thru the door, as Harry knelt to look at Ginny. Tom had the wand for the entire fight, only relinquishing it when he was vanquished.

Riddle didn’t move. Harry, sweating, managed to hoist Ginny half off the floor, and bent to pick up his wand again.

But his wand had gone.

“Did you see — ?”

He looked up. Riddle was still watching him — twirling Harry’s wand between his long fingers.

Then, after the battle...

There was a long, dreadful, piercing scream. Ink spurted out of the diary in torrents, streaming over Harry’s hands, flooding the floor. Riddle was writhing and twisting, screaming and flailing and then —

He had gone. Harry’s wand fell to the floor with a clatter and there was silence. Silence except for the steady drip drip of ink still oozing from the diary. The basilisk venom had burned a sizzling hole right through it.

So, yeah.. He could have done the whole thing as a squib, as long as he could speak 'Open' in parseltongue... Which we saw later could be done by a non-parseltongue, as Ron did exactly that in Hallows; he just had to have heard it before to know what sounds to make.

Answer 2

It's a major theme in the HP story that good people can do a lot of deep and powerful magic often even without any explicit magic. For example, Harry's open claim and commitment of loyalty to Dumbledore summoned Fawkes into the chamber, which could not be an accident as Fawkes did not know where it was prior to that. However, in the chamber of secrets Harry did do three magical things. The first is that he withdrew the sword of Gryffindor from the sorting hat, because of his bravery and desperately asking the hat for help. That in itself was a non-magical trigger, but the result was magical; the sword magically materialized in the hat. We see later that the sorting hat can be used by deserving people to magically summon Gryffindor's sword no matter where it was. Secondly, when Fawkes used its tears to heal Harry, he realizes that fact, so arguably he 'used' magic in a significant way. Thirdly, he used the basilisk fang to destroy the diary, instinctively. Basilisk venom is one of few substances magically potent enough to destroy a horcrux, so one could consider this to be a use of magic. Even if Harry was not aware of the potency of the venom, he guessed correctly that it might destroy the magical diary.

So there were no explicit spells, but still significant magic, used by Harry.