The Great Luckydo

A good place is in Revendreth at (49,45) on top of a tower, south-east of the raid entrance. There's a small platform which limit the move of your Chordy.

Tips for hunting with Chordy

1. 
   
2. It doesn't matter where you are looking for treasure, as long as Chordy can do his search, you can find all the items. So find somewhere that is flat and enemy free. Places I like include by covenant hall (in the main inside area) and the bank area in Oribos.
3. 
   
4. This is less of an activity to farm and more of a mindless distraction - when to do it, instead of running around Oribos in circles late at night like we know we all do. I really don't even pay attention to what I'm looting, I just keep clicking and searching.
5. 
   
6. Do follow Chordy while he's looking because there's a decent amount of the time that it spawns at his location. I feel like he tries to take you to the right spot but it doesn't always work. If it doesn't, start checking your known spawn points in the area (see below for tips on this). Also, do pay attention to where Chordy went at the start it's worth retracing those steps.
7. 
   
8. It is helpful to search from a consistent point, this limits the places that Chordy can put the items and so you learn where you need to check.
9. 
   
10. Don't search for too long because the items despawn, if you haven't found it and the timer's up, go back to your spot and start a new search.
11. 
    

I've found the best place for me is on top of the Seat of the Primus. Can easily spot the ground spawns, no NPC's or players to disrupt line of sight. Perfect.