Vaal Side Area Farming Locations?

I play PoE on console and I've been wanting to farm some Vaal areas ever since a Friend of mine said he got a Free Cosmetic from one of them, I don't know if that's true but if it is I'd like to know if there are ways to farm the Corrupted Areas without End-Game mapping. I've looked this up a few times and only found posts from either 2014 - 2015 and they don't seem to work as they may have been patched.

If anyone can tell me a good area to farm these places I'd appreciate it.

That's not at all true, you can't get cosmetics from normal play. Only by purchasing them or winning them in events.

You can use sacrifice fragments in the map device.

Since POE went to 10 acts I'm not familiar with which zones are good for side areas. Ideally you want a zone with a high chance of side areas, and also is easy to run through looking for them. The wiki will tell you which side areas can appear. It might also tell you where they appear, like walls, floor, etc.

I'm not sure what your friend meant by cosmetics. They may have been referring to the challenges in harbinger. One of the challenges requires side areas.

Before POE went to 10 acts I used to look for side areas in merciless Crossroads. They appeared in the side of cliffs. I'd run in a circle around the outer sides of the zone, starting and ending at the same connecting zone (usually Sin).