OP, I've done it and here's how: get a Feebas, preferably one with a nature that raises Sp. Atk, as they prefer blue (beauty) pokeblocks. Then go plant every Chesto and Oran berry you have somewhere easy to get to. Water them and wait. Leave it for a while, and then when they've produced berries, wait even longer. I was picking 12 berries form trees I'd left over night. then just make them all into blue pokeblocks, and spam feed them to the feebas until the word Beauty shines. then just level it up.
