This theory probably works when you use gold as your hedge. A...

This theory probably works when you use gold as your hedge. A gramme of gold still weighs a gramme regardless of what currencies are doing. Even if the global monetary system completely disintegrates, gold will still be valuable (for some reason). It has always been so.

But I believe it doesn't work like this for gold stocks. A gold stock's value comes from it being a share in a business, whose value comes from earning (and distributing) currency, which is produced by mining, refining and selling gold. If the monetary system breaks down then gold companies no longer have any value, and shares in those companies cease to have any value.

However that connection between gold and gold stocks in peoples' minds means they get bought a lot more when there is the threat of some upheaval. But in practice if the threat becomes reality then gold stocks go the same way as everything else.

I use gold stocks as a hedge in times on uncertainty.

In times of actual financial crisis though I think your only meaningful hedges are cash (relatively minor crisis) or actual gold (major crisis).