With the current low water levels on the Uruguay River in the section known as La Zona, popping plugs have been a good lure for catching monster dorado.
When using popping plugs, use the wrists to impart an erratic pop with the lure spitting and darting.
Noise is a key along with a fleeing action to trigger a strike. When a fish misses the popper, do not stop the retrieve. Instead keep the plug popping across the surface.
A few of the excellent poppers on the market include the Daiwa Saltiga Popper, Klures September Pop, River2Sea Shinn Pop110, and Sebile Splasher.
Test these lures in your local fishery before trying them in places such as La Zona.