I never had the patience when I was younger to try and find Feebas, and gave up after maybe 45 minutes of trying after deciding a Milotic wasn't worth the effort, when I wasn't planning on using it anyway. In hindsight, I wish I would've toughed it out and kept looking since they were 2 of the few Pokemon I had missing from my Hoenn Dex, but I might've been more motivated if there were more than just 6 tiles to find them in.