After obtaining the Lucky Amulet, return to Tree Town and get your next dance from Vera. Go to the warp room in the top right of the town and warp to the right area, or Arena Town at the top if you don't have it available. Continue east to where you got the barnacle at dock and do the Refresh dance with
+
. After a cutscene, go into the Metal Fish and talk to the first scientist. After a scene, you'll be in the Sea Lab and the achievement unlocks shortly after regaining control.