I don’t see the actual steps of your aunt’s method yet, so I can’t break down that exact trick—but I can show you the most common “2-minute, low-effort” ways people quickly hide brown spots (hyperpigmentation) that sound like what you’re describing.
One of the simplest tricks makeup artists use is basically this:
First, they tap a tiny amount of peach or orange color corrector directly on the brown spot. This neutralizes the darkness instead of just covering it.
Then, they lightly press a skin-toned concealer over it using a fingertip (no rubbing—just tapping so it blends into the skin).
Finally, they set it with a very thin dusting of powder or even just pressed tissue, so it doesn’t crease or shine.
That whole process really can take under 2 minutes once you get used to it, and it looks very natural in daylight.
If your aunt meant a no-makeup trick instead, another common one is using sunscreen + moisturizer well-blended over the area, which slightly blurs pigmentation so it’s less noticeable (not fully hidden, but softened fast).
If you want, tell me what exactly she uses (cream, kitchen item, makeup, etc.), and I’ll decode the exact method she’s using.